Representational Difference Analysis (RDA) reveals differential expression of conserved as well as novel genes during caste-specific development of the honey bee (Apis mellifera L.) ovary

In highly eusocial insects, such as the honey bee, Apis mellifera, the reproductive bias has become embedded in morphological caste differences. These are most expressively denoted in ovary size, with adult queens having large ovaries consisting of 150-200 ovarioles each, while workers typically have only 1-20 ovarioles per ovary. This morphological differentiation is a result of hormonal signals triggered by the diet change in the third larval instar, which eventually generate caste-specific gene expression patterns. To reveal these we produced differential gene expression libraries by Representational Difference Analysis (RDA) for queen and worker ovaries in a developmental stage when cell death is a prominent feature in the ovarioles of workers, whereas all ovarioles are maintained and extend in length in queens. In the queen library, 48% of the gene set represented homologs of known Drosophila genes, whereas in the worker ovary, the largest set (59%) were ESTs evidencing novel genes, not even computationally predicted in the honey bee genome. Differential expression was confirmed by quantitative RT-PCR for a selected gene set, denoting major differences for two queen and two worker library genes. These included two unpredicted genes located in chromosome 11 (Group11.35 and Group11.31, respectively) possibly representing long non-coding RNAs. Being candidates as modulators of ovary development, their expression and functional analysis should be a focal point for future studies. (C) 2011 Elsevier Ltd. All rights reserved.

Tooth Tissue Engineering: Optimal Dental Stem Cell Harvest Based on Tooth Development

Our long-term objective is to devise reliable methods to generate biological replacement teeth exhibiting the physical properties and functions of naturally formed human teeth. Previously, we demonstrated the successful use of tissue engineering approaches to generate small, bioengineered tooth crowns from harvested pig and rat postnatal dental stem cells (DSCs). To facilitate characterizations of human DSCs, we have developed a novel radiographic staging system to accurately correlate human third molar tooth developmental stage with anticipated harvested DSC yield. Our results demonstrated that DSC yields were higher in less developed teeth (Stages 1 and 2), and lower in more developed teeth (Stages 3, 4, and 5). The greatest cell yields and colony-forming units (CFUs) capability was obtained from Stages 1 and 2 tooth dental pulp. We conclude that radiographic developmental staging can be used to accurately assess the utility of harvested human teeth for future dental tissue engineering applications.

Laboratory evaluation of two native fishes from tropical North Queensland as biological control agents of subterranean Aedes aegypti

The ability of 2 freshwater fishes, eastern rainbow fish Melanotaenia splendida splendida and fly-specked hardyhead Craterocephalus stercusmuscarum stercusmuscarum. native to North Queensland to prey on immature Aedes aegypti was evaluated under laboratory conditions. The predation efficiency of the 2 species was compared to the exotic guppy, Poecilia reticulata, which is commonly used as a biological control agent of mosquito larvae. Of the 3 fish species tested, M. s. splendida was shown to be the most promising agent for the biological control of Ae. aegypti that breed in wells. Melanotaenia s. splendida consumed significantly greater numbers of immature Ae. aegypti than P. reticulata, irrespective of developmental stage or light conditions. Unlike C. s. stercusmuscarum, M, s. splendida could be handled, transported, and kept in captivity for extended periods with negligible mortality. However, M. s. splendida was also an efficient predator of Litoria caerulea tadpoles, a species of native frog found in wells during the dry season. This result may limit the usefulness of M. s. splendida as a biological control agent of well-breeding Ae. aegypti and suggests that predacious copepods, Mesocyclops spp., are more suitable. However, the use of M. s. splendida as a mosquito control agent in containers that are unlikely to support frog populations (e.g., aquaculture tanks and drinking troughs) should be given serious consideration.

GABA(A) receptor sites in the developing human foetus

GABA(A) receptor sites were characterised in cerebral cortex tissue samples from deceased neurologically normal infants who had come to autopsy during the third trimester of pregnancy. Pharmacological parameters were obtained from homogenate binding studies which utilised the 'central-type' benzodiazepine ligands [H-3]diazepam and [H-3]flunitrazepam, and from the GABA activation of [H-3]diazepam binding. It was found that the two radioligands behaved differently during development. The affinity of [H-3]flunitrazepam for its binding site did not vary significantly between preparations, whereas the [H-3]diazepam K-D showed marked regional and developmental variations: infant tissues showed a distinctly lower affinity than adults for this ligand. The density of [H-3]flunitrazepam binding sites increased similar to35% during the third trimester to reach adult levels by term, whereas [H-3]diazepam binding capacity declined slightly but steadily throughout development. The GABA activation of [H-3]diazepam binding was less efficient early in the trimester, in that the affinity of the agonist was significantly lower, though it rose to adult levels by term. The strength of the enhancement response increased to adult levels over the same time-frame. The results strongly suggest that the subunit composition of cortical GABA(A) sites changes significantly during this important developmental stage. (C) 2002 Elsevier Science B.V. All rights reserved.

Structure of the gut contents of Trichogramma australicum Girault (Hymenoptera : Trichogrammatidae) larvae fixed in situ in eggs of its host Helicoverpa armigera (Hubner) (Lepidoptera : Noctuidae)

Trichogramma australicum larvae develop most rapidly in younger eggs of its host, the pest lepidopteran Helicoverpa armigera . To establish how the developmental stage of the host affects the diet of T. australicum , larvae were fixed in situ in eggs of H. armigera of different ages and the structure of the egg contents and parasitoid gut contents examined histologically. Larvae feeding on newly laid host eggs contain primarily yolk particles in their gut, while larvae feeding on older hosts contain necrotic cells and yolk particles. The gut of T. australicum larvae does not contain organised tissue remnants, indicating that larvae feed primarily by sucking food into their pharynx and feed best on a mixture of particulate semisolids in a liquid matrix. Secretory structures of T. australicum larvae that could be involved in modifying the host environment were examined. The hindgut is modified to form an anal vesicle with a number of attributes suggesting that it may be a specialised secretory structure. The paired salivary glands open to the exterior via a common duct.

Leaf area and epicuticular wax content of Sida spp

Morpho-physiological characteristics and chemical composition are directly related to superior competitive ability of crops. This study intended to make a comparative analysis of dry matter production, leaf area and amount of epicuticular wax of three species of Sida spp: S. urens L., S. rhombifolia L. and S. spinosa L. Plants were collected at three growth stages: V1: stage described as up to 10 fully expanded leaves; V2: between 11 leaves and flowering; and R: after flowering. At stages V2 and R, the highest number of leaves was recorded for S. rhombifolia, followed by S. spinosa at V2 and S. urens at R. These results were relatively proportional to leaf area for all species. S. spinosa at the vegetative stage produced the highest values of specific leaf area (SLA), with no significant differences between species at the stage R. The amount of wax per unit of leaf area between species at the same developmental stage was significantly different only at the reproductive stage, where S. spinosa produced 23.18 and 6.23 fold more wax than S. urens and S. rhombifolia respectively. Between the growth stages of each species, there was decrease in the amount of wax with plant age and increase in leaf area (AFE), number of leaves and dry matter. The leaves of the Sida species exhibit different characteristics and this information can be used to optimize the use of herbicides in the control of these weeds.

Influence of foliar fertilization with manganese on germination, vigor and storage time of RR soybean seeds

ABSTRACTThis study aimed to evaluate the influence of foliar fertilizer doses containing Mn of phenological stages of suggested application in RR soybeans, to recover management damages with glyphosate at postemergence application on seed vigor in post-harvest and post six months storage. The seeds originated from a field experiment conducted , which included two applications of glyphosate, concomitant with foliar fertilizer in growth stages V4 and V6, with 0.00, 113.50 and 227.00 mg ha-1doses of Mn2+. Germination, GSI (Germination Speed Index), electrical conductivity tests and the first count of seeds were conducted. The application of Mn did not affect the physiological quality of RR soy in postharvest. However, in post-storage, higher doses of Mn had a negative effect on tests of abnormal seedlings, GSI and electrical conductivity. The applications of Mn, regardless of the developmental stage, did not interfere in the germination and first count tests, with and without storage. The electrical conductivity test showed a higher correlation with the seed germination test in the post-harvest treatment.

Lethal and sublethal effects of essential oils from Pittosporum undulatum and Hedychium gardnerianum on the egg parasitoid Trichogramma cordubensis (Hymenoptera: Trichogrammatidae

Dissertação de Mestrado, Biotecnologia em Controlo Biológico, 6 de Junho de 2013, Universidade dos Açores.

The perception, beliefs and practices toward genitourinary schistosomiasis by inhabitants of selected endemic areas (Edo/Delta States) in south-eastern Nigeria

Well-structured questionnaire on the perception, impression and response to genitourinary bilharziasis (Genitourinary schistosomiasis) was administered and explained in local languages: 'Igbo' 'Esan' 'Ezon' Itshekiri and Bini to 33815 inhabitants of selected endemic areas in south-eastern Nigeria from January, 1999 to December, 2001. Out of this number, 3815 (11.3%) were properly filled and returned. About 42.0% of the inhabitants admitted knowledge of the disease, while 14 (0.4%) knew about the aetiologic agent. About 181 (5.0%) who responded, admitted procuring treatment, while 100 (5.0%) declined to seek treatment of any sort. The relationships between water-bodies and human activities, and infection were well discussed. Amongst those who admitted knowledge of the disease but no knowledge of its etiologic agent, declined seeking treatment of any kind, but believe the disease is a natural phenomenon in ones developmental stage and therefore of no morbidity and mortality. Laboratory analysis of urine, faeces, semen and HVS was employed to assess questionnaire responses, and in some cases, physical examination was utilized to augment laboratory analysis in confirming urinal diagnosis. Haematuria was only directly related to egg count in the early part of life. Females were significantly haematuric and excreted more ova than males (p < 0.05). Headache (43.0%) and fever (31.0%) were major clinical signs while sexual pains (22.0%) were the least.

Cues for cancer stem cells origin

Dissertação para obtenção do Grau de Mestre em Genética Molecular e Biomedicina

Implementation of a pilot project for the treatment and prevention of substance abuse in children and adolescents : strengthening families for parents and youths 12-16

RESUMO: Antecendentes: Uma avaliação dos serviços de abuso de substâncias em Barbados identificou a necessidade de programas e serviços que são projetados especificamente para crianças e adolescentes. Objetivo: Realizar programa com base em evidências para reduzir a incidência de abuso de drogas entre crianças e adolescentes por meio do fortalecimento da unidade familiar através de parentalidade positiva, de maior funcionamento familiar e de resistência dos jovens. Método: Dois projetos-piloto foram realizadas com base no programa "Fortalecer as Famílias para Pais e Jovens de 12 a 16 anos (SFPY). O programa de nove semanas foi empregado como uma intervenção para criar laços familiares mais fortes, aumentar a resistência dos jovens e reduzir o abuso de drogas entre crianças e adolescentes de idades de 11 a 16 anos. A decisão foi tomada para incluir participantes de 11 anos desde que as crianças possam estar no primeiro ano da escola secundária nessa idade. IMPLEMENTATION OF SUBSTANCE ABUSE PILOT PROJECT FOR CHILDREN AND ADOLESCENTS 5 Resultados: Quinze famílias participaram em dois projetos-piloto e a avaliação final mostrou que os jovens após o programa, geralmente tornaram-se mais positivos sobre o seu lugar na unidade familiar e sentiram que sua participação no programa foi benéfica. Os pais, da mesma forma, relataram que eles conquistaram, com o programa uma relação mais positiva, uma melhor compreensão das necessidades, e consciência das mudanças de desenvolvimento de seus jovens. Desta forma, considera-se que o programa atingiu o resultado desejado de criar unidades familiares mais fortes. Conclusão: O Projeto Piloto “SFPY” foi bem sucedido em fazer pais e jovens mais conscientes de suas necessidades individuais e de responsabilidades dentro da unidade familiar. Como resultado, o relacionamentos das respectivas famílias melhorou. Estudos baseados em evidências têm demonstrado que um relação familiar mais forte diminui a incidência de uso e abuso de drogas na população adolescente, aumentando os fatores de proteção e diminuindo os fatores de risco. A implementação do programa, que foi desenvolvido e testado no ambiente norte-americano, demonstrou que era transferível para a sociedade de Barbados. No entanto, seu impacto total só pode ser determinado através de um estudo comparativo envolvendo um grupo de controle e / ou uma intervenção alternativa ao abuso de substâncias. Portanto, é recomendável que um estudo comparativo da intervenção SFPY deve envolver uma amostra representativa de adolescentes que estão em estágio de desenvolvimento anterior mais cedo. Evidências já demonstram que o programa é mais eficaz, com impacto mais longo sobre os jovens que participam em uma idade maisABSTRACT:Background: An evaluation of substance abuse services in Barbados has identified the need for programmes and services that are specifically designed for children and adolescents. Aim: To conduct an evidence-based programme to reduce the incidence of substance abuse among children and adolescents by strengthening the family unit through positive parenting, enhanced family functioning and youth resilience. Method: Two pilot projects were conducted based on the ‘Strengthening Families for Parents and Youths 12– 16’ (SFPY) programme. The nine-week programme was employed as an intervention to create stronger family connections, increase youth resiliency and reduce drug abuse among children and adolescents between the ages of 11 to 16. The decision was made to include participants from age 11 since children may be in the first year of secondary school at this age. IMPLEMENTATION OF SUBSTANCE ABUSE PILOT PROJECT FOR CHILDREN AND ADOLESCENTS 3 Results: Fifteen families participated in two pilot projects and an evaluation conducted at the conclusion showed that the youth were generally more positive about their perceived place in the family unit and felt that the being in the programme was generally beneficial. The parents similarly reported they had a more positive relationship with their youths and also had a better understanding of their needs, and an awareness of their developmental changes. This affirmed that the programme had achieved its desired outcome to create stronger family units. Conclusion: The SFPY Pilot Project was successful in making parents and youths more aware of their individual needs and responsibilities within the family unit. As a result relationships within their respective families were strengthened. Evidence-based studies have shown that enhanced family functioning decreases the incidence of substance use and abuse in the adolescent population by increasing protective factors and decreasing risk factors. The implementation of the programme, which was developed and tested in the North American environment, demonstrated that it was transferable to the Barbadian society. However, its full impact can only be determined through a comparative study involving a control group and/or an alternative substance abuse intervention. It is therefore recommended that a comparative study of the SFPY intervention should be delivered to a representative sample of adolescents who are at an earlier developmental stage. Evidence has shown that the programme is more effective, with longer impact on youths who participate at a younger age.

Ontogeny of swimming capacity in plaice (Pleuronectes platessa) larvae

Little is known regarding the swimming ability of the larvae of European plaice (Pleuronectes platessa) in relation to changes in total length (TL), dry weight (DW) and developmental stage, which is surprising given the importance of transport processes to the recruitment dynamics of this species in the North Sea and elsewhere. We investigated ontogenetic changes in the critical swimming speed (Ucrit) of plaice from hatching to the onset of metamorphosis (50 days post-hatch, dph) at 8 °C. The mean (±SD) TL and DW growth rates were 1.59 ± 0.81 and 7.7 ± 0.35 % d−1, respectively. Larvae were unable to swim at against a minimum current speed of <0.5 cm s−1 until 10 dph (7 mm TL), after which Ucrit significantly increased with increasing TL until the onset of metamorphosis and subsequent settlement. Mean (±SD) Ucrit was 0.38(0.35), 1.59(0.54), 2.27(0.49) and 2.99(0.37) cm s−1 for stage I (6.61 ± 2.64 mm TL), stage II (7.75 ± 0.60 mm TL), stage III (9.10 ± 1.00 mm TL) and stage IV (11.59 ± 0.85 mm TL) larvae, respectively. Larval TL, DW, DNA content, RNA content and Ucrit significantly increased, whereas sRD significantly declined as larvae developed from stage I to V. Although inter-individual differences in Ucrit (coefficient of variation, CV = 33 %) were as large as those in biochemical and morphological condition (CV’s of 21–42 %), differences in Ucrit were not significantly related to those in nutritional condition and larvae with lower DNA/DW had also better swimming abilities. These estimates should be useful to ongoing efforts to create individual- based models of the transport, foraging and growth of plaice larvae in the North Sea.

Gonad development in females of fiddler crab Uca rapax (Crustacea, Brachyura, Ocypodidae) using macro and microscopic techniques

The morphology of the ovaries in Uca rapax (Smith, 1870) was described based on macroscopic and microscopic analysis. Females were collected in Itamambuca mangrove, Ubatuba, state of São Paulo, Brazil. In the laboratory, 18 females had their ovaries removed and prepared for histology. Each gonad developmental stage was previously determined based on external and macroscopic morphology and afterwards each stage was microscopically described. The ovaries of U. rapax showed a pronounced macroscopic differentiation in size and coloration with the maturation of the gonad, with six ovarian developmental stages: immature, rudimentary, developing, developed, advanced and spent. During the vitellogenesis, the amount of oocytes in secondary stage increases in the ovary, resulting in a change in coloration of the gonad. Oogonias, primary oocytes, secondary oocytes and follicular cells were histologically described and measured. In female’s ovaries of U. rapax the modifications observed in the oocytes during the process of gonad maturation are similar to descriptions of gonads of other females of brachyuran crustaceans. The similarities are specially found in the morphological changes in the reproductive cells, and also in the presence and arrange of follicle cells during the process of ovary maturation. When external morphological characteristics of the gonads were compared to histological descriptions, it was possible to observe modifications that characterize the process in different developmental stages throughout the ovarian cycle and, consequently, the macroscopic classification of gonad stages agree with the modifications of the reproductive cells.

Morphological aspects of cell reabsorption in laying queens and workers of Apis mellifera (Hymenoptera, Apidae)

The occurrence of cell reabsorption in the ovaries of queens in several rates of laying eggs, artificially impeded of laying, and in nurse workers, of Apis mellifera (Linnaeus, 1758), was studied with light (LM) and transmission electron microscopy (TEM). Two types of structures were described and named by analogy with vertebrates ovarian structures, as corpus luteus, when resulting from the reabsorption of the follicular cells after ovulation, and corpus atresicus when resulting from total follicular reabsorption at any oocyte developmental stage. These structures have the same morphological characteristics and physiological signification in both castes. The corpus luteus occurrence indicates ovulation and its number is correspondent to the queen's rates of oviposition. The presence of this structure in nurse workers ovarioles shows that this caste may lay eggs. The incidence of corpus atresicus in queens decay with the increasing of the oviposition indicating that the inhibition of the normal sequence of oocyte maturation in the ovaries is deleterious. Both, corpus luteus and corpus atresicus incidence may be influenced by environmental factors.

Morphology and dynamics of male gametogenesis in Sympterygia bonapartii (Chondrichthyes, Rajidae) from Northern Patagonia

ABSTRACT The smallnose fanskate, Sympterygia bonapartii Müller & Henle, 1841 is one of the most disembarked items in commercial harbors in Argentina. In this work, the microscopic architecture of mature male gonads and the dynamics of cysts development are analyzed as a contribution to awareness of the reproductive biology of the species. Some biological data related to reproduction are given as well. Two seasons were sampled (fall and spring) and length classes's frequency distribution and maturity stages frequency distribution are given. Size at first sexual maturation for males was estimated at 57 cm of total length. Testes are symmetric, peer, lobed, with several germinal zones. Inside the gonads, there are many spermatocysts, containing reproductive cells at the same developmental stage. On the basis of their cytological and microanatomical features, several maturative degrees of the spermatogenic series were differentiated. Few Leydig cells were recognized at the interstitial tissue among cysts. The microscopic and semiquantitative analysis performed in this work provides morphological information about male gametogenesis and some biological data for the North Patagonian population of this economically and ecologically important species.