Protein polymorphism and genetic divergence in slow loris (Genus nycticebus)

In this study, protein electrophoresis was assayed to detect genetic variation in Genus Nycticebus. A total of 29 samples (2 N. coucang and 27 N. pygmaeus) were analyzed for 42 genetic loci. In the 27 samples of N. pygmaeus, 4 loci were observed to be polymorphic. Therefore, the estimated P value (proportion of polymorphic loci) is 0.095, the A value (average number of alleles each locus) is 1.045, and the H value (mean individual heterozygosity) is 0.040. After comparing the H of N. pygmaeus with those of other primates reported, we found that the protein variation in N. pygmaeus is slightly lower than the average level. Additionally, we also observed obvious allele difference between N. pygmaeus and N. coucang. There are no shared alleles between these two species in eight loci. The NEI's genetic distance between them was calculated as 0.2541, which falls in the spectrum of genetic difference between species in primates.

RAPD and AFLP techniques for the analysis of genetic relationships in two genera of Decapoda

RAPD was used fur analysing three (sub-)species of mitten crabs (Eriocheir sinensis, E. japonicus, and E. japonicus hepuensis) and three populations of E. sinensis. The results show that their relationships on DNA level are similar to the classical taxonomic hypotheses (Dai, 1991). No diagnostic RAPD marker could be found, but there were statistically significant genetic differences among these taxa (P < 0.001) or populations (P < 0.001). That is, the intraspecific similarities were larger than the interspecific similarities; the intrasubspecific similarities were larger than the intraspecific similarities; and the intrapopulational similarities were larger than the interpopulational similarities. In AFLP analysis, no significant genetic difference has been found between E. sinensis and E. japonicus, but AFLP markers among four species of Macrobrachium (M. rosenbergii. M. nipponense, M. hainanense, and M. asperulum) were found. The DNA similarities among these four species of Macrobrachium are in accordance with morphological similarities.

Population genetic structure of crimson snapper Lutjanus erythropterus in East Asia, revealed by analysis of the mitochondrial control region

The population genetic structure of the crimson snapper Lutjanus erythropterus in East Asia was examined with a 427-bp hypervariable portion of the mtDNA control region. A total of 262 samples were collected and 75 haplotypes were obtained. Neutrality tests (Tajima's and Fu's) suggested that Lutjanus erythropterus in East Asia had experienced a bottleneck followed by population expansion since the late Pleistocene. Despite the low phylogeographic structures in mtDNA haplotypes, a hierarchical examination of populations in 11 localities from four geographical regions using analysis of molecular variance (AMOVA) indicated significant genetic differentiation among regions (Phi(CT) = 0.08564, p < 0.01). Limited gene flow between the eastern region (including a locality in the western Pacific Ocean and two localities in the East Sea) and three geographic regions of the South China Sea largely contributed to the genetic subdivision. However, comparisons among three geographic regions of the South China Sea showed little to no genetic difference. Populations of Lutjanus erythropterus in East Asia are inferred to be divided into two major groups: an eastern group, including populations of the western Pacific Ocean and the East Sea, and a South China Sea group, consisting of populations from northern Malaysia to South China. The results suggest that fishery management should reflect the genetic differentiation and diversity in East Asia. (c) 2006 International Council for the Exploration of the Sea. Published by Elsevier Ltd. All rights reserved.

Molecular genetic investigation of the Neolithic population history in the western Carpathian Basin

Der Fokus dieser Dissertation ist die populationsgenetische Analyse der neolithischen Bevölkerungswechsel in den 6.-5. Jahrtausende vor Christus, die im westlichen Karpatenbecken stattfanden. Die Zielsetzung der Studie war, mittels der Analyse von mitochondrialer und Y-chromosomaler aDNA, den Genpool der sechs neolithischen und kupferzeitlichen Populationen zu untersuchen und die daraus resultierenden Ergebnisse mit anderen prähistorischen und modernen genetischen Daten zu vergleichen.rnInsgesamt wurden 323 Individuen aus 32 ungarischen, kroatischen und slowakischen Fundplätzen beprobt und bearbeitet in den archäogenetischen Laboren der Johannes Gutenberg-Universität in Mainz. Die DNA Ergebnisse wurden mit verschiedenen populationsgenetischen Methoden ausgewertet. Vergleichsdaten von prähistorischen und modernen eurasiatischen Populationen wurden dazu gesammelt.rnDie HVS-I Region der mitochondrialen DNA konnten bei 256 Individuen reproduziert und authentifiziert werden (mit einer Erfolgsrate von 85.9%). Die Typisierung der HVS-II Region war in 80 Fällen erfolgreich. Testend alle gut erhaltene Proben, die Y-chromosomale Haplogruppe konnte in 33 männlichen Individuen typisiert werden.rnDie neolithischen, mitochondrialen Haplogruppen deuten auf eine hohe Variabilität des maternalen Genpools hin. Sowohl die mitochondrialen als auch die Y-chromosomalen Daten lassen Rückschlüsse auf eine nah-östliche bzw. südwestasiatische Herkunft der frühen Bauern zu. Die Starčevo- und linearbandkermaischen-Populationen in westlichem Karpatenbecken (letztere abgekürzt als LBKT) und die linearbandkermaischen-Population in Mitteleuropa (LBK) haben so starke genetische Ähnlichkeit, dass die Verbreitung der LBK nach Mitteleuropa mit vorangegangenen Wanderungsereignissen zu erklären ist. Die Transdanubische aDNA Daten zeigen hohe Affinität zu den publizierten prähistorischen aDNA Datensätzen von Mitteleuropa aus den 6.-4. Jahrtausende vor Chr. Die maternal-genetische Variabilität der Starčevo-Population konnte auch innerhalb der nachfolgenden Populationen Transdanubiens festgestellt werden. Nur kleinere Infiltrationen und Immigrationsereignissen konnten während der Vinča-, LBKT-, Sopot- und Balaton-Lasinja-Kultur in Transdanubien identifiziert werden. Zwischen den transdanubischen Regionen konnten mögliche genetische Unterschiede nur in der LBKT und in der Lengyel-Periode beobachtet werden, als sich die nördlichen Gruppen von den südlichen Populationen trennten. rnDie festgestellte Heterogenität der mtDNA in Zusammenhang mit der Y-chromosomalen Homogenität in den Starčevo- und LBK-Populationen, weisen auf patrilokale Residenzregeln und patrilineare Abstammungsregeln in den ersten Bauergemeinschaften hin. rnObwohl die hier präsentierten Daten einen großen Fortschritt in der Forschung von aDNA und Neolithikum des Karpatenbeckens und Mitteleuropas bedeuten, werfen sie auch mehrere Fragen auf, deren Beantwortung durch zukünftige Genomforschungen erbracht werden könnte.

Novel risk loci for rheumatoid arthritis in Han Chinese and congruence with risk variants in Europeans

Objective To investigate differences in genetic risk factors for rheumatoid arthritis (RA) in Han Chinese as compared with Europeans. Methods A genome-wide association study was conducted in China with 952 patients and 943 controls, and 32 variants were followed up in 2,132 patients and 2,553 controls. A transpopulation meta-analysis with results from a large European RA study was also performed to compare the genetic architecture across the 2 ethnic remote populations. Results Three non-major histocompatibility complex (non-MHC) loci were identified at the genome-wide significance level, the effect sizes of which were larger in anti-citrullinated protein antibody (ACPA)-positive patients than in ACPA-negative patients. These included 2 novel variants, rs12617656, located in an intron of DPP4 (odds ratio [OR] 1.56, P = 1.6 × 10 -21), and rs12379034, located in the coding region of CDK5RAP2 (OR 1.49, P = 1.1 × 10-16), as well as a variant at the known CCR6 locus, rs1854853 (OR 0.71, P = 6.5 × 10-15). The analysis of ACPA-positive patients versus ACPA-negative patients revealed that rs12617656 at the DPP4 locus showed a strong interaction effect with ACPAs (P = 5.3 × 10-18), and such an interaction was also observed for rs7748270 at the MHC locus (P = 5.9 × 10-8). The transpopulation meta-analysis showed genome-wide overlap and enrichment in association signals across the 2 populations, as confirmed by prediction analysis. Conclusion This study has expanded the list of alleles that confer risk of RA, provided new insight into the pathogenesis of RA, and added empirical evidence to the emerging polygenic nature of complex trait variation driven by common genetic variants. Copyright © 2014 by the American College of Rheumatology.

Identification of putative virulence-associated genes of Haemophilus parasuis through suppression subtractive hybridization.

Haemophilus parasuis is the causative agent of Glässer's disease. Up to now 15 serovars of H. parasuis have been identified, with significant differences existing in virulence between serovars. In this study, suppression subtractive hybridization (SSH) was used to identify the genetic difference between Nagasaki (H. parasuis serovar 5 reference strain, highly virulent) and SW114 (H. parasuis serovar 3 reference strain, non-virulent). A total of 191 clones were obtained from the SSH library. Using dot hybridization and PCR, 15 clones were identified containing fragments that were present in the Nagasaki genome while absent in the SW114 genome. Among these 15 fragments, three fragments (ssh1, ssh13, ssh15) encode cell surface-associated components; three fragments (ssh2, ssh5, ssh9) are associated with metabolism and stress response; one fragment (ssh8) is involved in assembly of fimbria and one fragment (ssh6) is a phage phi-105 ORF25-like protein. The remaining seven fragments are hypothetical proteins or unknown. Based on PCR analysis of the 15 serovar reference strains, eight fragments (ssh1, ssh2, ssh3, ssh6, ssh8, ssh10, ssh11 and ssh12) were found in three to five of most virulent serovars (1, 5, 10, 12, 13 and 14), zero to two in three moderately virulent serovars (2, 4 and 15), but absent in the low virulent serovar (8) and non-virulent serovars (3, 6, 7, 9 and 11). In vivo transcription fragments ssh1, ssh2, ssh8 and ssh12 were identified in total RNA samples extracted from experimental infected pig lung by RT-PCR. This study has provided some evidence of genetic differences between H. parasuis strains of different virulence.

Estudo da ancestralidade materna da população do Rio de Janeiro: análise do DNA mitocondrial

As porções uniparentais do genoma humano, representadas pelo cromossomo Y e pelo DNA mitocondrial (DNAmt), contêm informação genética relacionada às heranças patrilinear e matrilinear, respectivamente. Além da aplicabilidade em genética médica e forense, o DNAmt tem sido utilizado como um importante marcador molecular em estudos sobre evolução para traçar inferências filogenéticas e filogeográficas sobre as populações humanas. A análise de linhagens de DNAmt presentes em diferentes populações mundiais levou à identificação de haplogrupos reunindo diversos haplótipos específicos dos grandes grupos étnicos: africanos, europeus, asiáticos e nativos americanos. A população brasileira é conhecida como uma das mais heterogêneas do mundo, resultado do processo de colonização do país, abrangendo mais de cinco séculos de miscigenação entre povos de diferentes continentes. Este trabalho teve como objetivo estimar a partir da análise do DNA mitocondrial as proporções ancestrais africanas, européias e ameríndias na população do Rio de Janeiro. Para isso foram sequencidas as regiões hipervariáveis HVI e HVII do DNAmt de 109 indivíduos não relacionados geneticamente residentes no Rio de Janeiro. Os haplogrupos foram classificados de acordo com o conjunto de polimorfismos dos haplótipos individuais. Programas estatísticas foram utilizados para a determinação de parâmetros de diversidade genética e comparações populacionais. A diversidade haplotípica foi estimada em 0,9988. Nossos resultados demonstraram na população do Rio de Janeiro percentuais de cerca de 60%, 25% e 15% de ancestralidades maternas africana, ameríndia e européia, respectivamente. Através da análise de distâncias genéticas, evidenciou-se que a população do Rio de Janeiro está mais próxima das populações brasilerias dos estados de São Paulo e Alagoas. Como descrito nos registros históricos, algumas regiões do país tiveram processos de colonização muito específicos que se refletem nas proporções ancestrais maternas e paternas observadas. Em relação ao DNAmt, não se verificou diferença genética significativa entre as populações do Rio de Janeiro e a de Angola, uma população africana. Os resultados obtidos estão em estreita concordância com os registros históricos e outros estudos genéticos acerca da formação da população brasileira

Intraspecific variation of isozymes in Arenicola marina (Polychaeta: Annelida)

Six enzyme systems, namely acid phosphatase, leucine aminopeptidase, phosphoglucose isomerase, tetrazolium oxidase, esterases and malate dehydrogenase were studied electrophoretically in Arenicola marina from various localities in United Kingdom. Out of 13 presumed loci, ten were found monomorphic. The three loci which appeared to be polymorphic are LAP-1, EST-2 and TO-1. Due to small sample size allele frequencies and genetic identity were not calculated. However, results indicate genetic difference among the population of A. marina.

Molecular characterization of three Rana grylio virus (RGV) isolates and Paralichthys olivaceus lymphocystis disease virus (LCDV-C) in iridoviruses

Three Rana grylio virus (RGV) isolates and lymphocystis disease virus (LCDV-C) were molecularly characterized by antigenicity comparison, Western blot detection of viral polypeptides, restriction fragment length polymorphism analysis of viral genomes, and MCP sequence analysis. Significant antigenicity differences existed among the three RGV isolates and LCDV-C. Western blot detection indicated that the viral polypeptides of three RGV isolates could be recognized by the anti-RGV9807 serum, whereas no bands were observed in the LCDV-C, and significant differences exist among the band patterns of three RGV isolates. Restriction fragment length polymorphism (RFLP) analysis was performed by digesting genomic DNA of the four iridovirus isolates with restriction endonucleases HindIII, KpnI, XbaI and BamHI. On the whole, obvious discrepancies existed between LCDV-C and RGV isolates, and some significant band pattern differences were also revealed between RGV9808 and RGV9506 (or RGV9807) in the profiles of restriction endonucleases Xbal, Kpn I and BamHI. PCR amplification and sequence analysis of MCP gene sequence further revealed their phylogenetic relationship among the three RGV isolates, LCDV-C and other iridoviruses. RGV9506, RGV9807 and RGV9808 are clustered together with other ranaviruses, such as FV3, BIV, TFV and ENHV, although the RGV9808 is more close to EHNV than to other ranaviruses. Additionally, LCDV-C is clustered with LCDV-1, the type species of genus Lymphocystisvirus. The current study provides clear evidence that significant genetic difference exists among the three RGV isolates. Therefore, further work on comparative genomic studies will contribute significantly to understanding of their taxonomic position and pathological mechanism. (C) 2005 Elsevier B.V. All rights reserved.

不同小麦品种（系）中主要矿质元素的含量比较及与品质的关系

采用微波消解、电感耦合高频等离子体原子发射光谱（ICP-AES）的方法,对62份不同小麦品种（系）中锌、铁、铜、钙、钠和钾的含量进行了测定。同时利用红外线品质测定仪对主要品质指标粗蛋白、湿面筋、沉降值进行了测定。结果表明，不同小麦品种（系）中各种矿质元素的含量存在差异，2006年小麦品种中铁含量变幅为18.55-58.19 ug/g，平均为30.83ug/g ，最高与最低的相差39.64ug/g；锌含量变幅为5.70-25.80 ug/g，平均为15.13ug/g ，最高与最低相差20.10ug/g。2008年小麦品种（系）中铁含量变幅为16.68-52.25 ug/g，平均为30.10ug/g，最高与最低相差35.58ug/g；锌含量变幅为12.29-33.47 ug/g，平均为21.11ug/g，最高与最低相差21.18ug/g；钙含量变幅为167.53-348.80ug/g，平均为248.59ug/g，最高与最低相差192.59ug/g；铜含量变幅为2.32-5.83 ug/g，平均为2.98ug/g，最高与最低的相差3.61ug/g；钾含量变幅为1822.71-4414.91 ug/g，平均为2617.87ug/g，最高与最低的相差2634.72ug/g；钠含量变幅为10.25-39.82 ug/g，平均为23.05ug/g，最高与最低的相差29.57ug/g。 两年不同小麦品种（系）中矿质元素的含量分析结果表明：铁、铜、钙、钠和钾含量年际变化不明显,说明小麦对铁、铜、钙、钠和钾的吸收较稳定；锌含量变化较大，可能受环境的影响比较大。分析各矿质元素含量与粗蛋白、湿面筋、沉降值及元素之间的相关关系，结果表明，锌含量与粗蛋白含量呈极显著正相关关系，相关系数为0.317，与湿面筋含量之间呈显著正相关，相关系数达到0.246；铁含量与粗蛋白含量呈显著的正相关关系，相关系数是0.262；铜、钙、钠和钾含量与粗蛋白含量、湿面筋和沉降值之间存在正相关，但不显著，其中钠与沉降值之间为负相关。表明施锌或铁对提高小麦粗蛋白和湿面筋有显著效应，其余矿质元素有促进作用但不明显。 利用RAPD分子标记技术对川育23、41058、川育20及其父母本进行分析，力图从分子水平找到小麦矿质元素含量之间的差异性，琼脂糖电泳结果表明不同的小麦品种（系）间扩增出了差异条带。 以上研究结果，将对筛选“微量营养强化型”小麦新材料，选育“微量营养强化型”小麦新品种奠定基础。 62 different wheat cultivars was digested with HNO3 in a tightly closed vessel heated under micro-wave,then contents of zinc，iron,copper，calcium，sodium and potassium were determined by inductively coupled plasma-atomic emission spectroscopy(ICP-AES)．The main indexes of wheat quality such as total protein、wet glu and sedimentation volume were detected by Infratec 1255 Food & Feed Analyzer at the same time.The obtained results showed that variation for all of the mineral elements concentrations among different cultivars were observed .In 2006, the amplitude variation of the iron content was 18.55-58.19 ug/g,the average value was 30.83ug/g,and 39.64ug/g between the highest-content cultivar and the lowest one; the amplitude variation of the zinc content was 5.70-25.8 ug/g,the average value was 15.13ug/g,and 20.10ug/g between the highest-content cultivar and the lowest one.In 2008, the amplitude variation of the iron content was 16.68-52.25 ug/g,the average value was 30.10ug/g,and 35.58ug/g between the highest-content cultivar and the lowest one; the amplitude variation of the zinc content was 12.29-33.47 ug/g,the average value was 21.11ug/g,and 21.18ug/g between the highest-content cultivar and the lowest one; the amplitude variation of the calcium content was 167.53-348.80ug/g,the average value was 248.59ug/g,and 192.59ug/g between the highest-content cultivar and the lowest one; the amplitude variation of the copper content was 2.32-5.83 ug/g,the average value was 2.98ug/g,and 3.61ug/g between the highest-content cultivar and the lowest one; the amplitude variation of the potassium content was 1822.71-4414.91 ug/g,the average value was 2617.87ug/g,and 2634.72ug/g between the highest-content cultivar and the lowest one; the amplitude variation of the sodium content was 10.25-39.82 ug/g,the average value was 23.05ug/g,and 29.57ug/g between the highest-content cultivar and the lowest one. Analysis was made on the annual variation of mineral elements content in different Wheat cultivars ,the result shows:there is no obvious difference of iron ,copper ,sodium、calcium and potassium concentrations in wheat cultivars, suggesting the absorption of the iron, copper, sodium、calcium and potassium by wheat are relatively steady ,but zinc concentrations change obviously ,maybe influenced heavily by environment . The correlation between mineral elements 、mineral elements and total protein、mineral elements and sedimentation volume as well as mineral elements and wet glut were analysed in this paper, the result showed that there was significant positive correlation between zinc content and total protein (the correlation coefficient is 0.317), positive correlation between zinc content and wet glu (the correlation coefficient is 0.246), positive correlation between iron content and total protein (the correlation coefficient is 0.262). there was positive but not obvious correlation between the contents of copper, calcium, sodium or potassium and total protein, wet glut or sedimentation volume,among which was negative correlation between sodium and sedimentation volume.It was indicated zinc or iron fertilization has prominent effects in improving the total protein in wheat, the rest mineral elements have Non- obvious facilitation. The study then forecasted the genetic difference of different wheat by the molecular marker of RAPD in order to find differences in molecular level. Chuanyu23、41058、chuanyu20 as well as their male and female parents were analysed by RAPD markers,Agarose gel electrophoresis of DNA revealed the appearance of differential bands . The above-mentioned results of this study establish the foundation to screening the new materials of wheat of " strengthening type of micro- nutrition ", and to breeding the new wheat cultivars of" strengthening type of micro- nutrition ".

小麦中微量元素锌铁硒的含量的分析

本研究应用微波消解ICP-AES 法对62 个小麦品种及3 个地区土壤的锌铁硒含量进行了分析测定，发现不同小麦品种中微量元素含量差异很大，姊妹系间也存在差异。含铁量最高与最低的小麦品种铁含量相差29.68mg/kg。含锌量最高与最低的小麦品种锌含量相差46.70 mg/kg。含硒量最高与最低的小麦品种硒含量相差0.056 mg/kg。对不同地点的小麦及土壤中锌铁硒含量进行方差分析，发现双流和西昌两地种植小麦的铁含量和硒含量均有显著差异，西昌和荣县种植的锌含量有显著差异。在3 个地点中双流种植小麦硒含量最高，西昌种植小麦的铁和锌含量最高。 通过对小麦微量元素含量与土壤中微量元素含量进行了相关性分析，结果表明：小麦中的锌铁含量与土壤中的锌铁含量呈显著正相关，土壤中铁与锌含量呈极显著正相关，小麦中铁与锌含量也呈极显著正相关。随着土壤微量元素锌铁的提高，小麦中的锌铁元素含量同时提高，而且小麦对两种元素的吸收互相促进。土壤中的硒含量与锌铁含量呈负相关。小麦中硒含量也与锌铁含量也呈负相关。说明锌和铁与硒互相拮抗。小麦硒含量与土壤硒含量呈正相关，但不显著。表明土壤硒含量可以影响小麦硒含量，但不是决定因素，小麦硒含量与小麦自身因素有关。 对姊妹系G290（高硒含量）和G289（低硒含量）进行抗重金属胁迫和抗旱性实验发现，高硒品种G290的抗逆性优于低硒品种G289。 利用RAPD 技术对7 个姊妹系进行遗传差异分析发现，高硒材料G290出现了特异条带，分别标为1、2、3、4，其他姊妹系品种中未发现特异条带，回收4 条特异条带并连接转化，得到目的片段1、2、3 的重组子，进行测序。NCBI 中结果显示没有找到植物中的同源序列，说明特异序列可能是未发现的基因片段，推测可能与小麦硒含量有关，有待进一步研究。 以上研究结果，对小麦营养研究及功能性小麦的筛选和栽培具有指导作用。 In this study, we determinated the contents of zinc, iron, selenium in 62 wheat cultivars and soil samples of three regions by method of microwave digestion/ ICPAES,found that there was great difference of zinc, iron, selenium contents in different wheat cultivars as well as different sister lines. Iron content difference was 29.68 mg/kg between the highest-iron-content cultivar and the lowest one, and zinc content difference was 46.70 mg/kg , selenium content difference was 0.056 mg/kg. Anova analysis was made on contents of zinc, iron, selenium in wheat and soil samples of different locations, significant differences of Fe and Se contents were found between wheat in Shuangliu and Xichang, significant difference of Zn content was found between wheat in Xichang and Rongxian. Se content in wheat of Shuangliu was highest, Fe and Zn contents in wheat of Xichang were highest. Relativity analysis was made on three trace elements in Wheat and in soil, the result showed that there was significant positive correlation of zinc, iron content between in Wheat and in soil, as well as between Fe and Zn both in wheat and in soil. With the improving of Zn, Fe contents in soil, contents of Zn and Fe in wheat increased and absorption of Zn and Fe in wheat will mutual promote. Negative correlation of Se and Zn contents was found in wheat and soil, but not significant, that meant the antagonism of Se and Zn. Positive correlation of Se content in wheat and soil was found. High selenium content G290 and low selenium content G289 in sister lines were selected for heavy metal stress and drought resistance experiments, the result showed that the resistance of high-selenium-content cultivar was better than low selenium one. Analysis on genetic difference was made by RAPD, and specific bands were selected, marked 1,2,3,4, no more specific bands were found in other sister lines.4 bands were recovered, ligated to T-vector and transformed E.coli. Three recombinant plasmids were obtained and sequenced. NCBI Blast showed there was no homology with other plants. It implied that these fragments probably be new genes and maybe were related to selenium in wheat. It needs further research. This paper would be useful for the study of wheat nutrition as well as selection and cultivation of functional wheat.

Growth of eight Pacific abalone families at three temperatures

Growth rates, measured as shell length and body weight daily growth, were studied in the eight families of Pacific abalone, Haliotis discus hannai Ino, reared at 12, 16 and 20 degrees C for 40 d respectively. The results show that J(1)Rh family grew the best at 12 degrees C, with growth rates of (32.88 +/- 4.66) mu m/d and (5.24 +/- 1.84) mg/d. C(1)Jm family had the highest growth rates of (58.00 +/- 2.00) mu m/d and (9.71 +/- 1.21) mg/d at 16 degrees C. J(1)Jm family ranked the first at 20 degrees C, with growth rates of (66.00 +/- 1.76) mu m/d and (10.99 +/- 0.34) mg/d. RjRh family had the slowest growth rates at all three temperatures. Shell length growth rates were 18.25, 33.00 and 43.13 mu m/d respectively, while body weight growth rates were 2.47, 2.56 and 4.75 mg/d respectively. Both temperature and family had significant effect on growth rates (P<0.05). At 16 and 20 degrees C, maternal effects on growth rates were not significant (P>0.05), but paternal effects on growth rates were significant (P<0.05). Results of this study indicate genetic difference among the families and importance of selecting male breeders in the commercial hatchery.

Sub-Arctic populations of European lobster (Homarus gammarus) in Northern Norway.

The European lobster is distributed throughout the south and western regions of the Norwegian coast. A previous lobster allozyme investigation (1993) in the Tysfjord region, north of the Arctic Circle demonstrated that the lobster population from this region was genetically different from lobster samples collected in other parts of Norway. More detailed investigation including supplementary extensive sampling and additional allozyme, microsatellite and mtDNA analyses are reported here. This investigation supports the genetic distinctness of the Tysfjord population and shows that this is mainly due to a reduction (60�70%) in gene diversity (observed heterozygosities and number of alleles) compared with lobsters from more southern regions. In addition to the Tysfjord region, the comprehensive sampling also included lobsters found in the adjacent Nordfolda fjord system. Genetic analyses provided evidence for significant differences between the lobster populations of Tysfjord and Nordfolda, even though they are separated by a coastal distance of only 142 km. The two populations were also different with regards to several biological characteristics such as body size. The genetic difference between these two geographically close populations is likely to be due to the local hydrological conditions, preventing larval dispersal between the fjord systems. Assessment of lobster abundance in the north-west region suggests that the sub-arctic lobster populations are geographically isolated.

Le syndrome métabolique chez les congéniques du rat Dahl : influence de la diète et rôle du récepteur de l'ANP

L’hypertension artérielle et l’obésité sont deux composantes conjointement reliées du syndrome métabolique. Les récepteurs de l’ANP (GCA) et de l’oxyde nitrique (GCs) ont des propriétés diurétiques, natriurétiques, vasodilatatrices et sont liés au contrôle de la pression. Des études récentes ont démontré leur implication dans l’obésité. Hypothèse : Une différence génétique au niveau du gène GCA pourrait contribuer à des différences physiologiques. La composante lipidique et/ou sodique de la diète pourrait influencer la fonction rénale, cardiaque et les valeurs anthropométriques différemment chez les souches congéniques. Objectifs : (1) Déterminer l’effet de la composante lipidique et sodique des diètes; (2) Évaluer l’influence de GCA sur la réponse physiologique des souches congéniques; (3) Expliquer les mécanismes physiologiques procurant une réduction de la pression artérielle chez la souche SM9. Méthodologie : Des modèles congéniques du rat Dahl (DSS) hypertendu, nourri avec une diète riche en gras (HF) ou normale (NF), ont été utilisés pour démontrer l’impact d’un segment chromosomique d’origine normotendue. Résultats : La souche SM9 a une prise de poids plus importante que SM12 et DSS sur diète HF malgré un apport alimentaire équivalent. La souche SM9 présente également un ratio masse adipeuse/masse maigre plus élevé que SM12 et DSS. Nous n’avons observé aucune augmentation de la pression artérielle en réponse à la diète HF pour les 3 souches malgré une augmentation du dommage rénal pour les 3 souches. Le dommage rénal est plus important chez DSS que pour les 2 congéniques. La réponse diurétique à l’ANP est plus élevée chez SM9 et est influencée par le contenu en sel dand la diète. La perte glomérulaire plus importante chez le rat DSS semble compensée par une augmentation de la réponse à l’ANP par les glomérules résiduels. Il y a une corrélation entre l’activité de GCA en réponse à l’ANP, les niveaux d’ARNm et le nombre de répétition du dinucléotide TA dans son promoteur. Le rat DSS présente une hypertrophie cardiaque plus importante que les deux souches congénique et ceci n’est pas modifié par la diète HF. Conclusion : Nos études ont permis de mettre en évidence un effet génétique impliquant le segment chromosomique normotendu contenant GCA dans la réponse à une diète HF chez le rat DSS.

L'épigénétique, moteur de l'évolution d'un vertébré asexué

L’objectif de cette thèse est de déterminer l’étendue de la variabilité épigénétique, plus particulièrement du polymorphisme de méthylation de l’ADN, non liée à la variabilité génétique dans les populations asexuées en milieu naturel. Cette évaluation nous a permis de mieux cerner l’importance que peuvent avoir les processus épigénétiques en écologie et en évolution. Le modèle biologique utilisé est l’hybride clonal du complexe gynogénétique Chrosomus eos-neogaeus. Malgré une homogénéité génétique, une importante variabilité phénotypique est observée entre les hybrides d’une même lignée clonale mais retrouvés dans des environnements différents. L’influence des processus épigénétiques apporte une explication sur ce paradoxe. L’épigénétique se définit comme une modification de l’expression des gènes sans changement de la séquence d’ADN. La diversité des phénotypes peut entre autre s’expliquer par des patrons de méthylation différentiels des gènes et/ou des allèles des gènes entre les hybrides génétiquement identiques. La diversité des lignées épiclonales peut quant à elle s’expliquer par la colonisation de plusieurs lignées épiclonales, s’établir en réponse à l’environnement ou de façon aléatoire. Plusieurs méthodes seront utilisées afin de survoler le génome des hybrides clonaux pour mettre en évidence le polymorphisme de méthylation de l’ADN à l’échelle de l’individu et entre les individus de différentes populations.