64 resultados para carnivora


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We have made a set of chromosome-specific painting probes for the American mink by degenerate oligonucleotide primed-PCR (DOP-PCR) amplification of flow-sorted chromosomes. The painting probes were used to delimit homologous chromosomal segments among human, red fox, dog, cat and eight species of the family Mustelidae, including the European mink, steppe and forest polecats, least weasel, mountain weasel, Japanese sable, striped polecat, and badger. Based on the results of chromosome painting and G-banding, comparative maps between these species have been established. The integrated map demonstrates a high level of karyotype conservation among mustelid species. Comparative analysis of the conserved chromosomal segments among mustelids and outgroup species revealed 18 putative ancestral autosomal segments that probably represent the ancestral chromosomes, or chromosome arms, in the karyotype of the most recent ancestor of the family Mustelidae. The proposed 2n = 38 ancestral Mustelidae karyotype appears to have been retained in some modern mustelids, e.g., Martes, Lutra, ktonyx, and Vormela. The derivation of the mustelid karyotypes from the putative ancestral state resulted from centric fusions, fissions, the addition of heterochromatic arms, and occasional pericentric inversions. Our results confirm many of the evolutionary conclusions suggested by other data and strengthen the topology of the carnivore phylogenetic tree through the inclusion of genome-wide chromosome rearrangements. Copyright (C) 2002 S. KargerAG, Basel.

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Multidirectional comparative chromosome painting was used to investigate the karyotypic relationships among representative species from three Feliformia families of the order Carnivora ( Viverridae, Hyaenidae and Felidae). Complete sets of painting probes derived from flow-sorted chromosomes of the domestic dog, American mink, and human were hybridized onto metaphases of the spotted hyena (Crocuta crocuta, 2n = 40) and masked palm civet (Paguma larvata, 2n = 44). Extensive chromosomal conservation is evident in these two species when compared with the cat karyotype, and only a few events of chromosome fusion, fission and inversion differentiate the karyotypes of these Feliformia species. The comparative chromosome painting data have enabled the integration of the hyena and palm civet chromosomes into the previously established comparative map among the domestic cat, domestic dog, American mink and human and improved our understanding on the karyotype phylogeny of Feliformia species. Copyright (C) 2005 S. Karger AG, Basel.

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Phylogenetic relationships among 37 living species of order Carnivora spanning a relatively broad range of divergence times and taxonomic levels were examined using nuclear sequence data from exon1 of the IRBP gene (approximate to1.3 kb) and first intron

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Pancreatic ribonuclease (RNASE1) is a digestive enzyme that has been recognized to be one of the most attractive model systems for molecular evolutionary studies. The contribution of RNASE1 gene duplication to the functional adaptation of digestive physio

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The monophyletic group Caniformia in the order Carnivora currently comprises seven families whose relationships remain contentious. The phylogenetic positions of the two panda species within the Caniformia have also been evolutionary puzzles over the past

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追溯生物界不同生物类型的起源及进化关系,即重建生物类群的系统发育树是进化生物学领域中一个十分重要的内容,并日益受到广泛的关注。美国和一些欧洲国家已率先启动了类似人类基因组计划的"生命之树,,计划(TreeofLife,TOL),将对生物学研究的发展产生深远影响。本研究瞄准了"生命之树"这一国际关注的焦点问题,选择具有重要进化理论意义和保护生物学价值的食肉目进行研究,除采用流行的多个线粒体基因外,还筛选多个有效的核基因标记,通过多基因序列数据的整合分析,构建可靠的食肉目分子系统树。此外,我们在食肉目部分物种的一个内含子区域发现了SINE家族的插入,考虑到这个内含子区域可能是SINE家族序列的一个插入热点,我们还增加了一些胎盘类哺乳动物目对这个内含子区域发生的多次SINE家族插入进行了详尽的进化研究。世界现生食肉目动物共计有11科280种,一般将它们归为两大超科,犬型超科(熊科,犬科,洗熊科,锄科,海狮科,海象科和海豹科)和猫型超科(灵猫科、猫科、鼠狗科和獴科)。犬型超科由于包含的物种种类繁多而且形态差异极"大,因此物种之间的系统发育关系方面争论颇多,难以解决。我们选用四个核基因序列片段和一个线粒体蛋白编码基因(共4417个碱基)对16个大型超科食肉目代表物种进行研究,探讨这一超科中科间的系统发育关系以及两个熊猫(大,小熊猫)的位置。结果表明不同基因在各分枝上表现出不同的解决能力,核基因和线粒体基因不含有冲突的,而是含有互补的系统发育信号,因而当把它们合并在一起进行系统发育分析时得到了一个大部分分枝都有很高支持程度的系统树拓扑结构。系统发育重建支持犬科是犬型超科中最早分歧的谱系,洗熊科和勃科的关系最近。小熊猫是洗熊科和触科的姐妹群,大熊猫是熊科中最早分歧的成员。鳍脚类(海狮科,海象科和海豹科)和熊科依次是由洗熊科,融科和小熊猫组成的进化枝最近的姐妹群。其中,鳍脚类和熊科的系统发育学位置在合并所有基因片段进行的ML和贝叶斯分析方法中都有较高的支持率和后验概率,但是在孵分析中的支持率却很低。因此,鳍脚类,熊科和由洗熊科,融科,小熊猫组成的进化枝三者之间的系统发育关系的解决将是以后食肉目犬型超科科水平系统发育学研究的趋势和重点。食肉目中不仅各科之间的进化关系扑朔迷离,科内的系统发育关系也很不清楚,尤其是熊科和猫科。因为这两个科都是在非常近期才发生物种分化的类群,代表了快速的进化辐射和间隔时间非常短的物种形成事件,因而重建科内各物种之间的系统发育关系对于系统学家来说是一项艰巨,极富挑战性的任务,也是造成熊科和猫科物种系统发育关系一直无法得到完全解决的重要原因。我们首次从两个核基因的角度,并与以前发表的五个线粒体基因数据进行单独和合并分析来探讨所有熊科物种(8个)的系统发育关系(约4kb)。结果不仅证实了目前普遍接受的观点,包括眼镜熊是除大熊猫以外最早分歧的熊科物种,以及棕熊和北极熊的姐妹群关系,而且进一步支持了亚洲黑熊和美洲黑熊之间的紧密关系,但是就在大多数以前的线粒体基因研究暗示懒熊极有可能是Ursus属中分歧最早的熊科物种时,我们的核基因分析提出新的假说,强烈支持懒熊和马来熊之间的姐妹群关系,使得懒熊和马来熊的系统发育位置又要成为将来熊科系统发育学研究中讨论的热点。另外,我们也探讨了核基因和线粒体基因表现出不一致系统发育信号的可能原因。猫科物种一般分成三大谱系:家猫谱系,豹谱系和虎猫谱系。其中由Panthera属和一些中等体型大小的猫类组成的豹谱系分化时间最近而且包含的物种最多,因此围绕它的系统发育学未解决的问题也最多。我们首次使用三个核基因对猫科中豹谱系部分物种系统发育关系进行探讨,同时还测定了两个完整线粒体编码基因,并结合以前发表的其它四个线粒体基因片段进行单独和结合分析,了解猫科豹谱系物种的进化历史。另外,我们还比较了这9个基因序列片段在进化特征和猫科系统发育关系应用价值方面的异同点。通过对14个猫科部分物种,主要为豹谱系物种的多个线粒体和核基因序列片段的综合分析,得到了一些非常有价值的重要结论,包括Panthera属的单源性以及Panthera属内部物种之间新的系统发育关系,云豹与Panthera属关系最近,美洲狮和猎豹是姐妹群,兔孙仍然属于家猫谱系等等。本研究中的核基因DNA在追溯如此近期才分化的猫科类群过程中积累的序列差异较少,因而贡献非常有限,它们可能会更适合用来解决食肉目中更高水平的物种之间系统发育关系。此外,当我们使用FGB基因第七内含子进行食肉目犬型超科各科和猫科部分物种的系统发育关系研究时,发现犬科代表物种和两个猫科物种中的不同位置上都发现了SINE片段的插入。我们又增加了除食肉目以外的部分哺乳动物目代表物种(共30个分类群)来进一步分析FGB基因第七内含子发生的多次SINEs家族插入事件。我们的结果表明:在所有哺乳动物内含子中的直源位置都发现了起源于tRNA的M琅元件,除了啮齿目。研究发现啮齿目小鼠中较高的序列变异速率以及大鼠中随着寄主DNA的大段丢失而发生了罕有的遗失是造成啮齿目中MIR缺失的原因。此外,在我们分析的12个哺乳动物目中,食肉目,偶蹄目和兔形目的FGB基因第七内含子不同位置还发现了至少五次谱系特异性SINE家族的独立插入事件。在食肉目中,三个独立的CANSINEs插入支持了这个SINE家族在食肉目所有类群中都有分布的假说(即"pan-camivores"假说)。研究中最重要的发现就是那些谱系特异的sINE家族有插入到己存在的MIRs内部或MIRs附近的强烈倾向,表明MIR很有可能是其它SINEs连续插入的"热点"区域,因而使这个内含子区域有如此多的逆转座子插入。我们认为SINEs要比以前所意识到的具有更大的插入"灵活性"和区域"特异性"。另外,本论文还重点介绍了现代系统发育学中常用的系统发育重建方法和策.略以及随着基因组时代的到来,"系统发育基因组学(P坤logenomics))'这门崭新的交叉学科在"重建生命之树"方面所具有的巨大优势和潜力。

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Tesis (Maestría en Ciencias con Especialidad en Manejo de Vida Silvestre) UANL

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The feeding habits of the maned wolf were studied in southeast Brazil to understand its response towards changes in the environment and in relation to its prey. By occurrence, miscellaneous fruits, small mammals and wolf`s fruit were the most consumed items. Armadillos, small mammals and wolf`s fruit ( Solanum lycocarpum) provided most of the ingested biomass. While wolf`s fruit and small mammals were mainly consumed in the dry season, other miscellaneous fruits were taken mostly in the wet season. There was selectivity in the predation on some small mammal species. The maned wolf`s diet followed patterns similar to those found in more pristine areas.

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Mass and length growth models were determined for male (n = 69) and female (n = 163) Australian fur seals (Arctocephalus pusillus doriferus) collected at a breeding colony on Seal Rocks (38˚31′S, 145˚06′E), Bass Strait, in south-east Australia, between February and November during 1970–72. Growth was best described by the logistic model in males and the von Bertalanffy model in females. Asymptotic mass and length were 229 kg and 221 cm for males, and 85 kg and 163 cm for females. In all, 95% of asymptotic mass and length were attained by 11 years and 11 years, respectively, in males compared with 9 years and 5 years, respectively, in females. Males grew in length faster than females and experienced a growth spurt in mass coinciding with the onset of puberty (4–5 years). The onset of puberty in females occurs when approximately 86% of asymptotic length is attained. The rate of growth and sexual development in Australian fur seals is similar to (if not faster than) that in the conspecific Cape fur seal (A. p. pusillus), which inhabits the nutrient-rich Benguela current. This suggests that the low marine productivity of Bass Strait may not be cause of the slow rate of recovery of the Australian fur seal population following the severe over-exploitation of the commercial sealing era. Sternal blubber depth was positively correlated in adult animals with a body condition index derived from the residuals of the mass–length relationship (males: r2 = 0.38, n = 19, P < 0.001; females: r2 = 0.22, n = 92, P < 0.001), confirming the validity of using such indices on otariids. Sternal blubber depth varied significantly with season in adult animals. In males it was lowest in winter and increased during spring prior to the breeding season (r2 = 0.39, n = 19, P < 0.03) whereas in females it was greatest during winter (r2 = 0.05, n = 122, P< 0.05).

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Esse trabalho foi realizado em uma remanescente de Mata Atlântica, na região metropolitana de Porto Alegre, Parque Estadual de Itapuã (PEI), Rio Grande do Sul, Brasil e teve como objetivos avaliar aspectos da ecologia dos graxains do mato Cerdocyon thous e do campo Pseudalopex gymnocercus (horário de atividade, atividade ao longo das estações do ano e fases lunares, ecologia reprodutiva, densidade na área de estudo e simpatria). Além disso, foi proposta desse estudo avaliar o uso de estações-de-cheiro para acessar informações sobre atividade e uso de hábitat de C. thous. Para isso foram utilizados diferentes métodos. Para avaliação de aspectos da ecologia dos canídeos foram realizadas transecções para observação direta dos animais. Esses dados foram georeferenciados e comparados com fatores ambientais (índice de vegetação NDVI, estação do ano, fase lunar e hora). Para o cálculo da densidade, animais foram capturados e marcados durante um ano. Utilizou-se uma estimativa da área amostral e do tamanho populacional médio através do método Jolly-Sebber. Para avaliação da ecologia reprodutiva, foram agrupadas as informações obtidas com os métodos anteriores. Com relação às estações-de-cheiro, foram montados 22 plots de areia com um metro de diâmetro e distancia de 100 metros entre si com um atrativo olfativo ao centro. As estações foram montadas e revisadas duas vezes por mês durante um ano. As informações de visitação foram cruzadas com dados ambientais (NDVI altitude, proximidade de cursos d’água, cobertura vegetal) e temporais (estação-do-ano e lua). Os principais resultados obtidos foram os seguintes: graxains-do-campo e do mato ocorrem em simpatria apenas na metade sul do PEI, sendo que os primeiros utilizam áreas com pouca vegetação e areia, enquanto o graxaim-do-mato ocupa todos os ambientes disponíveis. Ambos têm atividade preferencialmente noturna. O graxaim-do-mato ocorre em uma densidade média estimada de 0,78 ind/km2, estando esse valor dentro do encontrado na literatura. Os graxains-do-mato apresentam maior atividade no outono, diminuindo na primavera, época essa em que ocorrem os nascimentos dos filhotes. A maior atividade foi registrada na lua crescente e a menor na lua nova. Com relação às estações-de-cheiro, estas demonstraram ser um bom método para avaliar atividade de espécies de canídeos em curtos períodos de tempo e, associadas a técnicas de geoprocessamento, podem fornecer informações sobre uso de hábitat.