Effects of histone hyperacetylation on the preimplantation development of male and female bovine embryos

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Comparison of embryo yield and pregnancy rate between in vivo and in vitro methods in the same Nelore (Bos indicus) donor cows

To investigate why the preferred means to produce bovine embryos in Brazil has changed from in vivo to in vitro, we compared these two approaches in the same Nelore cows (n = 30) and assessed total embryo production and pregnancy rates. Without a specific schedule, all cows were subjected to ultrasound-guided ovum pick up (OPU)/in vitro production (IVP) and MOET, with intervals ranging from 15 to 45 d between procedures, respectively. To produce in vivo embryos, cows were superovulated and embryos were recovered nonsurgically from 1 to 3 times (1.4 +/- 0.6). whereas OPU/IVP was repeated from 1 to 5 times (3.2 +/- 1.2) in each donor cow during a 12-mo interval. Embryos obtained from both methods were transferred to crossbred heifers. on average. 25.6 +/- 15.3 immature oocytes were collected per OPU attempt. The average number of embryos produced by OPU/IVP (9.4 +/- 5.3) was higher (P < 0.05) than the MOET method (6.7 +/- 3.7). However, pregnancy rates were lower (P < 0.05) following transfer of IVP (33.5%) versus in vivo-derived embryos (41.5%) embryos. Embryonic losses between Days 30 and 60 and fetal sex ratio were similar (P > 0.05) between in vivo and in vitro-derived embryos. We concluded that in Nelore cows, with an interval of 15 d between OPU procedures, it was possible to produce more embryos and pregnancies compared to conventional MOET. (C) 2009 Elsevier B.V. All rights reserved.

Cytochemical characterization of the endomembranous system during oocyte secondary growth in Serrasalmus spilopleura (Teleostei, Characiformes, Characidae)

The endomembranous system of Serrasalmus spilopleura oocyte secondary growth was analysed using structural and ultrastructural cytochemical techniques. In vitellogenic oocytes, the endoplasmic reticulum components, the nuclear envelope intermembranous space, some Golgi dictiossomes, lysosomes, yolk granules, regions of the egg envelope and sites of the follicle cells react to acid phosphatase detection (AcPase). The cortical alveoli, some heterogeneous cytoplasmic structures, regions of the egg envelope, and sites of the follicle cells are strongly contrasted by osmium tetroxide and zinc iodide impregnation (ZIO). The endoplasmic reticulum components, some vesicles, and sites of the follicle cells also react to osmium tetroxide and potassium iodide impregnation (KI). The biosynthetic pathway of lysosomal proteins, such as acid phosphatase, required for vitellogenesis, involves the endoplasmic reticulum, Golgi complex, vesicles with inactive hydrolytic enzymes, and, finally, lysosomes. In S. spilopleura oocytes at secondary growth, the endomembranous system takes part in the production of the enzymes needed for vitellogenesis, and in the metabolism of yolk exogenous components (AcPase detection). The endomembranous system compartments also show reduction capacity (KI reaction) and are involved in the metabolism of proteins rich in SH-groups (ZIO reaction).

Activity of the Ovarian Germinal Epithelium in the Freshwater Catfish, Pimelodus maculatus (Teleostei: Ostariophysi: Siluriformes): Germline Cysts, Follicle Formation and Oocyte Development

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Structural and ultrastructural characterization of the embryonic development of Pseudoplatystoma spp. hybrids

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Apoptotic and developmental effects of bovine Herpesvirus type-5 infection on in vitro-produced bovine embryos

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Influence of the breed of bull (Bos taurus indicus vs. Bos taurus taurus) and the breed of cow (Bos taurus indicus, Bos taurus taurus and crossbred) on the resistance of bovine embryos to heat

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Oocyte morphometry in female dogs (Canis familiaris, Linnaeus, 1758)

In the present study, the ovaries of 15 healthy bitches divided into three groups according to age were analysed by histology and morphometry: group 1 (1-3 years), group 2 (> 3-5 years) and group 3 (> 5-7 years). After ovariosalpingohysterectomy, the ovaries were fixed, routinely processed for embedding in paraffin and stained with haematoxylin-eosin. The following morphometric parameters were analysed: maximum and minimum diameter (mu m), perimeter (mu m), area (mu m(2)) and roundness of the cytoplasm and nucleus of oocytes from different types of follicles. Significant differences in the cytoplasmic and nuclear parameters of follicular oocytes between the experimental groups were determined by ANOVA and the Tukey test (5%). For the biotechnology of reproduction, the present results showed that in vitro maturation yielded the best performance for oocytes from primordial follicles in group 3 females and for oocytes embedded in secondary and tertiary follicles in group 2 females. In addition, the present findings will help in the diagnosis and prognosis of diseases affecting bitches, and will especially contribute to a better understanding of these cells by researchers in the field of histology and canine reproduction.

Expression and Function of Fibroblast Growth Factor 18 in the Ovarian Follicle in Cattle

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Histopathology of Rhipicephalus sanguineus (Acari: Ixodidae) ticks fed on resistant hosts

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Evaluation of developmental changes in bovine in vitro produced embryos following exposure to bovine Herpesvirus type 5

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Biologia populacional de Pareiorhina rudolphi (Loricariidae, Hypostominae) na microbacia do Ribeirão Grande, serra da Mantiqueira oriental, Estado de São Paulo

Pareiorhina rudolphi was sampled in streams of the Ribeirao Grande system, eastern Serra da Mantiqueira (22[degree]47[minute]08[second]S, 45[degree]28[minute]17[second] W). Samplings were carried out using an electrofishing device, during the months of July/2001, October/2001, February/2002 and April/2002. Sex-ratio diverged significantly from the expected 1: 1 ratio([chi]2 = 6.53; p < 0.05), standing at 1.6:1 (female: male). The spawning period for Pareiorhina rudolphi lasts from spring to summer, with, the highest observed, in October and February by the gonadosomantic index and the relative condition factor coincided with the spawning period. The length at sexual maturity of P. rudolphi is about 4.45 cm for both sexes. The absolute fecundity was low, and ranged from 4 to 11 oocytes. The periphyton was used as a direct food source by the species, which remain attached to the substrate with their large circular lips, and use their conspicuous Slightly Yellowish teeth to graze the periphyton. The growth parameters, natural mortality rate and survival rate for P, rudolphi were respectively: K = 0.35 year-1, L[infinity] = 7.2 cm, tmax = 8.6 years, M = 1.1 year-1, S = 33%. The characteristics presented by P. rudolphi occur in the environment function of a population adjustment, and not of species abundance.

Histochemical and ultrastructural cytochemistry of glycogen in ovarioles of Neoponera villosa ants (hymenoptera : ponerinae)

In Neoponera villosa ants, we found ovaries of the polytrophic meroistic type which is characterized by the presence of nurse cells forming together with the oocyte, the so-called follicles. The nurse cells have the primary function of supplying the oocyte with RNA, but they contribute to the supply of other elements such as glycogen. With the objetive of detecting the presence of this substance in the ovarioles of workers and queens of N. viillosa ants the ovaries were removed and processed according to electron microscopy technic for glycogen detection. Glycogen is a common element in insect oocytes and is abundantly distributed in the cytoplasm of N. villosa workers and queens. However, in ovarian follicles it can only be detected at stages II and III of development. Glycogen synthesis probably occurs predominantly in nurse cells which transfer it into the oocyte through the nourish pore. This process requires high energy expenditure that justify the large numbers of mitochondria associated with glycogen in the nurse cell cytoplasm. The amount of glycogen in the nurse cells of queens is slightly greater than workers.

Developmental and behavioral effects of postnatal amitraz exposure in rats

The effects of postnatal amitraz exposure on physical and behavioral parameters were studied in Wistar rats, whose lactating dams received the pesticide (10 mg/Kg) orally on days 1, 4, 7, 10, 13, 16 and 19 of lactation; control dams received distilled water (1 ml/kg) on the same days. A total of 18 different litters (9 of them control and 9 experimental) born after a 21- day gestation were used. The results showed that the median effective time (ET50) for fur development, eye opening, testis descent and onset of the startle response were increased in rats postnatally exposed to amitraz (2.7, 15.1, 21.6 and 15.3 days, respectively) compared to those of the control pups (1.8, 14.0, 19.9 and 12.9 days, respectively). The ages of incisor eruption, total unfolding of the external ears, vaginal and ear opening and the time taken to perform the grasping hindlimb reflex were not affected by amitraz exposure. Pups from dams treated with amitraz during lactation took more time (in seconds) to perform the surface righting reflex on postnatal days (PND) 3 (25.0 ±2.0), 4 (12.3 ± 1.2) and 5 (8.7 ± 0.9) in relation to controls (10.6 ± 1.2; 4.5 ± 0.6 and 3.4 ± 0.4, respectively); the climbing response was not changed by amitraz. Postnatal amitraz exposure increased spontaneous motor activity of male and female pups in the open-field on PND 16 (140± 11)and 17(124± 12), and 16 (104±9), 17 (137 ± 9) and 18 (106 ± 8), respectively. Data on spontaneous motor activity of the control male and female pups were 59 ± 11 and 69 ± 10 for days 16 and 17 and 49 ± 9, 48 ± 7 and 56 ± 7 for days 16, 17 and 18, respectively. Some qualitative differences were also observed in spontaneous motor behavior; thus, raising the head, shoulder and pelvis matured one or two days later in the amitraz- treated offspring. Postnatal amitraz exposure did not change locomotion and rearing frequencies or immobility time in the open-field on PND 30, 60 and 90. The present findings indicate that postnatal exposure to amitraz caused transient developmental and behavioral changes in the exposed offspring and suggest that further investigation of the potential health risk of amitraz exposure to developing human and animal offsprings may be warranted.

Complete replacement of the mitochondrial genotype in a Bos indicus calf reconstructed by nuclear transfer to a bos taurus oocyte

Due to the exclusively maternal inheritance of mitochondria, mitochondrial genotypes can be coupled to a particular nuclear genotype by continuous mating of founder females and their female offspring to males of the desired nuclear genotype. However, backcrossing is a gradual procedure that, apart from being lengthy, cannot ascertain that genetic and epigenetic changes will modify the original nuclear genotype. Animal cloning by nuclear transfer using host ooplasm carrying polymorphic mitochondrial genomes allows, among other biotechnology applications, the coupling of nuclear and mitochondrial genotypes of diverse origin within a single generation. Previous attempts to use Bos taurus oocytes as hosts to transfer nuclei from unrelated species led to the development to the blastocyst stage but none supported gestation to term. Our aim in this study was to determine whether B. taurus oocytes support development of nuclei from the closely related B. indicus cattle and to examine the fate of their mitochondrial genotypes throughout development. We show that indicus:taurus reconstructed oocytes develop to the blastocyst stage and produce live offspring after transfer to surrogate cows. We also demonstrate that, in reconstructed embryos, donor cell-derived mitochondria undergo a stringent genetic drift during early development leading, in most cases, to a reduction or complete elimination of B. indicus mtDNA. These results demonstrate that cross-subspecies animal cloning is a viable approach both for matching diverse nuclear and cytoplasmic genes to create novel breeds of cattle and for rescuing closely related endangered cattle.