Somatic development and embryo yield in crossbred F1 mice generated by different mating strategies.

The aim of this study was to evaluate different mating strategies among endogamic strains to create F1 populations of mice, minimising the effect of inbreeding depression on somatic development and embryo yield. Females from the strains Swiss, CBA and C57Bl/6 were divided in nine experimental mate arrangements. The total numbers of pups born alive per dam and somatic development, estimated by weighing and measuring the crown-rump length, were recorded. Superovulation response was evaluated in outbreed females. Litter size differed among endogamic dams, irrespective of the sire. Somatic development results suggest heterosis and imprinting phenomena, once a differential parental effect was demonstrated. There was no difference in corpora lutea, ova or embryos recovered (P > 0.05), but recovery and viability rates differ among F1 groups (P < 0.05). The association of dam prolificity with somatic development and superovulation response of the pups should be considered for experimental F1 populations establishment. The use of outbreed animals, however, did not reduce response variability to hormone treatment

Genetic variability of an endangered Bromeliaceae species (Pitcairnia albiflos) from the Brazilian Atlantic rainforest.

Pitcairnia albiflos is a Bromeliaceae species endemic to Brazil that has been included as data-deficient in the extinction risk list of Brazilian flora. We analyzed genetic variability in P. albiflos populations using RAPD markers to investigate population structure and reproductive mechanisms and also to evaluate the actual extinction risk level of this species. Leaves of 56 individuals of P. albiflos from three populations were collected: Urca Hill (UH, 20 individuals), Chacrinha State Park (CSP, 24 individuals) and Tijuca National Park (TNP, 12 individuals). The RAPD technique was effective in characterizing the genetic diversity in the P. albiflos populations since it was possible to differentiate the populations and to identify exclusive bands for at least two of them. Even if there is low genetic diversity among them (CSP-UH = 0.463; CSP-TNP = 0.440; UH-TNP = 0.524), the populations seem to be isolated according to the low genetic diversity observed within them (H(pop) CSP = 0.060; H(pop) UH = 0.042; H(pop) TNP = 0.130). This fact might be the result of clonal and self-reproduction predominance and also from environmental degradation around the collection areas. Consequently, it would be important to protect all populations both in situ and ex situ to prevent the decrease of genetic variability. The low genetic variability among individuals of the same population confirms the inclusion of this species as critically endangered in the risk list for Brazilian flora

Cloprostenol administration in the first week postpartum reduces expression of oxytocin receptors in the endometrium in Holstein-Zebu cows.

ABSTRACT The present study investigated the hormonal profile and expression of prostaglandin F2? (PGF2?), oxytocin and estrogen receptors in uterine tissues of postpartum cows treated with cloprostenol. Twenty HolsteinZebu crossbred cows were treated with saline solution (treatment CONT) or cloprostenol (treatment CLO), both administered two and five days postpartum. Blood samples were collected on days two, seven, 14, 21 and 28 postpartum for progesterone, PGF2? metabolite (PGFM) and estradiol determination, and endometrial biopsy was performed in order to quantify the expression of oxytocin receptor (OXTR), prostaglandin F receptor (PTGFR) and estrogen receptor 1 (ERS1) genes. In the CLO treatment, expression of OXTR was reduced (P0.05) between treatments was found for PTGFR and ERS1 expression. Estrogen concentrations increased progressively until day 14 (P<0.05) and the highest OXTR expression and lowest PTGFR expression were observed on day 14 (P<0.05) in both treatments. Serum PGFM concentrations were high throughout the experiment. In conclusion, cloprostenol administration at days two and five of postpartum seems to reduce OXTR expression in the endometrium in crossbred cows

Are superovulation protocols realy efficient for embryo production in inbred mice lineages?

Edição dos resumos da 20 Reunião Anual da Sociedade Brasileira de Tecnologia de Embriões, Araxá, 2006

Somatic development and embryo yield in crossbred F1 mice generated by different mating strategies

The aim of this study was to evaluate different mating strategies among endogamic strains to create F1 populations of mice, minimising the effect of inbreeding depression on somatic development and embryo yield. Females from the strains Swiss, CBA and C57Bl/6 were divided in nine experimental mate arrangements. The total numbers of pups born alive per dam and somatic development, estimated by weighing and measuring the crown-rump length, were recorded. Superovulation response was evaluated in outbreed females. Litter size differed among endogamic dams, irrespective of the sire. Somatic development results suggest heterosis and imprinting phenomena, once a differential parental effect was demonstrated. There was no difference in corpora lutea, ova or embryos recovered (P > 0.05), but recovery and viability rates differ among F1 groups (P < 0.05). The association of dam prolificity with somatic development and superovulation response of the pups should be considered for experimental F1 populations establishment. The use of outbreed animals, however, did not reduce response variability to hormone treatment

Somatic development and embryo yield in crossbred F1 mice generated by different mating strategies / Desenvolvimento somático e produção de embriões em camundongos cruzados F1 gerados com diferentes estratégias de cruzamento

Submitted by Ana Maria Fiscina Sampaio ([email protected]) on 2013-01-07T17:46:21Z No. of bitstreams: 1 Batista, RITP et al. Somatic development and....pdf: 340801 bytes, checksum: a2380fc1cdc0690247aa9b0d7b4d2259 (MD5)Made available in DSpace on 2013-01-07T17:46:21Z (GMT). No. of bitstreams: 1 Batista, RITP et al. Somatic development and....pdf: 340801 bytes, checksum: a2380fc1cdc0690247aa9b0d7b4d2259 (MD5) Previous issue date: 2010Centro de Ensino Superior de Juiz de Fora. Juiz de Fora, MG, BrasilUniversidade Federal de Juiz de Fora. Juiz de Fora, MG, BrasilUniversidade Federal de Viçosa. Viçosa, MG, BrasilFundação Oswaldo Cruz. Centro de Pesquisas Gonçalo Moniz. Salvador, BA, BrasilEmpresa Brasileira de Pesquisa Agropecuária. Embrapa Gado de Leite. Juiz de Fora, MG, BrasilObjetivou-se neste estudo avaliar diferentes estratégias de cruzamento entre linhagens endogâmicas para a formação de populações de camundongos F1, minimizando o efeito da depressão por endogamia nos resultados de desenvolvimento somático e produção de embriões. Fêmeas das linhagens Swiss, CBA e C57Bl/6, foram distribuídas em nove possíveis cruzamentos. Foram registrados o número de filhotes nascidos vivos por matriz e o desenvolvimento somático dos mesmos, mensurado pelo peso e comprimento. A resposta superovulatória foi avaliada nas fêmeas cruzadas. O tamanho das ninhadas diferiu entre as linhagens das matrizes, de forma independente da linhagem dos reprodutores. Os resultados do desenvolvimento somático sugerem a ocorrência de heterose e imprinting, uma vez que foi demonstrado um efeito parental diferenciado. Não foram observadas diferenças no número de corpos lúteos, estruturas ou embriões recuperados (P > 0,05), mas as taxas de recuperação e o percentual de embriões viáveis diferiram entre os grupos (P 0.05), but recovery and viability rates differ among F1 groups (P < 0.05). The association of dam prolificity with somatic development and superovulation response of the pups should be considered for experimental F1 populations establishment. The use of outbreed animals, however, did not reduce response variability to hormone treatmen