Repercussions of mild diabetes on pregnancy in Wistar rats and on the fetal development

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

Evaluation of neonatally-induced mild diabetes in rats: Maternal and fetal repercussions

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

Neospora caninum infection dynamics in dairy cattle

Neospora caninum is considered in many countries as one of the key abortion agents in cattle. This study aims to investigate the parasite behavior in dairy cattle in the municipality of Avar,, SP, Brazil, where abortions frequently occur. An ELISA was performed to compare two samplings on a total of 615 animals; tests were performed in the same herds with a gap of 3 years. An increase in the percentage of reactive animals was observed, ranging from 21.6% at the first sampling to 38.9% at the second sampling. of the 176 animals tested at both samplings, 61.93% retained a non-reactive status, 15.9% retained a reactive status, 19.88% switched from non-reactive to reactive and 2.27% switched from reactive to non-reactive. of the 100 animals with reproductive disturbances, 50% presented anti-Neospora antibodies, thereby indicating the presence of the protozoa. When comparing cows and their respective female offspring, a predominance of horizontal infection was observed. Moreover, considering the significant percentage of animals that switched from non-reactive to reactive and the abundant presence of dogs among the herds, the N. caninum transmission may be attributed to presence of carnivores.

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.

Thelytokous parthenogenesis in the fungus-gardening ant Mycocepurus smithii (Hymenoptera: Formicidae)

The general prevalence of sexual reproduction over asexual reproduction among organisms testifies to the evolutionary benefits of recombination, such as accelerated adaptation to changing environments and elimination of deleterious mutations. Documented instances of asexual reproduction in groups otherwise dominated by sexual reproduction challenge evolutionary biologists to understand the special circumstances that might confer an advantage to asexual reproductive strategies. Here we report one such instance of asexual reproduction in the ants. We present evidence for obligate thelytoky in the asexual fungus-gardening ant, Mycocepurus smithii, in which queens produce female offspring from unfertilized eggs, workers are sterile, and males appear to be completely absent. Obligate thelytoky is implicated by reproductive physiology of queens, lack of males, absence of mating behavior, and natural history observations. An obligate thelytoky hypothesis is further supported by the absence of evidence indicating sexual reproduction or genetic recombination across the species' extensive distribution range (Mexico-Argentina). Potential conflicting evidence for sexual reproduction in this species derives from three Mycocepurus males reported in the literature, previously regarded as possible males of M. smithii. However, we show here that these specimens represent males of the congeneric species M. obsoletus, and not males of M. smithii. Mycocepurus smithii is unique among ants and among eusocial Hymenoptera, in that males seem to be completely absent and only queens (and not workers) produce diploid offspring via thelytoky. Because colonies consisting only of females can be propagated consecutively in the laboratory, M. smithii could be an adequate study organism a) to test hypotheses of the population-genetic advantages and disadvantages of asexual reproduction in a social organism and b) inform kin conflict theory. For a Portuguese translation of the abstract, please see Abstract S1. © 2009 Rabeling et al.

Efeito da exposição à fumaça de cigarro durante a prenhez e a lactação de ratas e sua prole sobre parâmetros séricos e morfométricos

PURPOSE: to investigate the effect of cigarette smoke exposure on body and tissue weight gain, serum parameters and milk yield during pregnancy and lactation in rats, and the impact on offspring from birth toil young adulthood. METHODS: 40 Wistar pregnant rats were randomly divided into: CG - not exposed to cigarette smoke and sacrificed at the end of pregnancy; CL - not exposed to cigarette smoke and sacrificed at the end of lactation; FG - exposed to cigarette smoke and sacrificed at the end of pregnancy; FL - exposed to cigarette smoke and sacrificed at the end of lactation. The offspring were separated by gender and divided according to their mothers' groups. Tissue weight, body weight and serum parameters were evaluated in rats and offspring. Milk yield per pup was calculated. RESULTS: body weight was decreased in FL during lactation (CL=267.0±7.2; FL=235.5±7.2 g*, *p<0.05). Adipose tissue was not detected in the CL and FL groups, and was reduced in FG compared to CG (CG=3.3±0.3; FG=2.4±0.3 g*, *p<0.05). Rats exposed to cigarette smoke had higher blood glucose levels (CG=113±17, CL=86±16, FG=177±21*, FL=178±23 mg/dL*, *p<0.05 CG versus FG e CL versus FL), CL and FL groups presented lower HDL-cholesterol with no change in total cholesterol. Finally, rats exposed to cigarette smoke had lower milk yield compared to unexposed rats (CL=6.7±0.4, FL=5.4±0.3 g*, *p<0.05). In offspring from the FG and FL groups, there was a decrease of body weight from birth to young adulthood, with no changes in gastrocnemius, liver or heart weights in any group, and adipose tissue was no detected in female offspring. There was an increase in blood glucose in offspring of both sexes from rats exposed to cigarette smoke (males: Pcg=107±10.5, Pcl=115±8.6, Pfg=148±16.8*, Pfl=172±11.2**; females: Pcg=109±27.2, Pcl=104±9.7, Pfg=134±20.0*, Pfl=126±13.3**; p<0.05 *Pcg versus Pfg and **Pcl versus Pfl). CONCLUSIONS: exposure to cigarette smoke provokes impairment of morphometric and serum parameters during pregnancy and lactation both in mothers and offspring, which is maintained during young adulthood.

Efeitos cardiovasculares da exposição pré-natal à permetrina, isoladamente ou em associação à desnutrição intra-uterina, em ratos adultos e o comportamento materno nessas condições

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Avaliação do estresse oxidativo no sangue e na placenta de ratas com diabete de intensidade moderada

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Hiperglicemia materna: efeitos no cuidado materno e no desenvolvimento e comportamento dos descendentes

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Avaliação do desenvolvimento do sistema genital e da funçao reprodutiva da prole feminina de ratos Wistar expostos à cisplatina durante a peri-puberdade

Pós-graduação em Biologia Geral e Aplicada - IBB

Exposure to lard-based high-fat diet during fetal and lactation periods modifies breast cancer susceptibility in adulthood in rats

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

Diabete moderado induzido em diferentes fases da vida de ratas Wistar: repercussões na reprodução materna e na freqüência de anomalias fetais

Experimental models are necessary to elucidate pathophysiological mechanisms not yet understood in humans. To evaluate the repercussions of the diabetes, considering two methodologies, on the pregnancy of Wistar rats and on the development of their offspring. In the 1st induction, female offspring were distributed into two experimental groups: Group streptozotocin (STZ, n=67): received the β-cytotoxic agent (100mg STZ/kg body weight - sc) on the 1st day of the life; and Non-diabetic Group (ND, n=14): received the vehicle in a similar time period. In the adult life, the animals were mated. After a positive diagnosis of pregnancy (0), female rats from group STZ presenting with lower glycemia than 120 mg/dL received more 20 mg STZ/kg (ip) at day 7 of pregnancy (2nd induction). The female rats with glycemia higher than 120mg/dL were discarded because they reproduced results already found in the literature. In the mornings of days 0, 7, 14 and 21 of the pregnancy glycemia was determined. At day 21 of pregnancy (at term), the female rats were anesthetized and killed for maternal reproductive performance and fetal development analysis. The data were analyzed using Student-Newman-Keuls, Chi-square and Zero-inflated Poisson (ZIP) Tests (p<0.05). STZ rats presented with increased rates of pre (STZ=22.0%; ND=5.1%) and post-implantation losses (STZ=26.1%; ND=5.7%), reduced rates of fetuses with appropriate weight for gestational age (STZ=66%; ND=93%) and reduced degree of development (ossification sites). Conclusion: Mild diabetes led a negative impact on maternal reproductive performance and caused intrauterine growth restriction and impaired fetal development

Intrauterine growth restricted rats exercised before and during pregnancy: maternal and perinatal repercussions

This study aimed at evaluating the effect of swimming before and during pregnancy on rats born with intrauterine growth restriction (IUGR) and their offspring. For this, nondiabetic and streptozotocin-induced severely diabetic (SD) pregnant rats were mated and generated offspring with appropriate (control, C) and small (IUGR) for pregnancy age, respectively. Following that, C and IUGR groups were further distributed into nonexercised control (C), exercised control (Cex), nonexercised IUGR (IUGR), and exercised IUGR (IUGRex). IUGR rats presented lower mating rate than control rats. Regardless of physical exercise IUGR rats presented decreased body weight from birth to lactation. At 90 days of life, IUGR rats presented glucose intolerance. Maternal organ weights were increased and relative adiposity of IUGRex rats was lower than Cex. IUGR and IUGRex offspring presented reduced body weight than C and Cex, respectively. IUGRex dams presented an increased rate of appropriate for pregnancy age newborns. IUGEex male and female offspring relative brain weight was increased compared with Cex. Therefore, swimming before and during pregnancy prevented glucose intolerance, reduced general adiposity, and increased maternal and offspring organ weight in rats, showing the benefit of physical exercise for IUGR rats.

Perinatal exposure to androgen excess and the effects on the rat uterine estradiol responsiveness

Androgen exposure during sexual development induces alterations in steroidal target tissues. The objective of this study was to evaluate the uterine responsiveness to estradiol after perinatal androgenization. Pregnant Wistar rats were exposed to corn oil or testosterone propionate at 0.05, 0.1, or 0.2 mg/kg from gestational day 12 until postnatal day 21. Female offspring was challenged with estradiol (E2 ) after weaning (0.4 mg/kg) and at adulthood (10 or 100 µg/day), when the pituitary response was also evaluated. At adulthood, control and 0.05 mg/kg groups presented a uterine weight increment when exposed to 100 µg/day of E2 , 0.1 mg/kg group only responded to 10 µg/day of E2 , and the 0.2 mg/kg group showed increased uterine weight at both doses. The pituitary weight was similarly increased after estradiol stimulation in all experimental groups. In conclusion, testosterone propionate exposure induced an abnormal stimulation of uterine tissue growth by estrogen stimulus without affecting pituitary response. More studies are needed to clarify whether these alterations are capable of impairing the reproductive capacity of the female tract. © 2015 Wiley Periodicals, Inc. Environ Toxicol, 2015.

Efeitos da exposição gestacional, lactacional e juvenil às dietas com deficiência e suplementação de zinco e suscetibilidade a carcinogênese da mama em fêmeas Sprague-Dawley

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)