Animal Reproduction最新文献

The effects of antibiotics on sperm longevity in collared peccary (Pecari tajacu) fresh diluted semen was evaluated. Semen samples from six adult males were collected by electroejaculation and diluted in Tris-citrate-fructose alone (control) and plus streptomycin-penicillin (2 mg/ml-2000 IU/ml) or gentamicin (70 µg/ml). Membrane integrity and functionality, mitochondrial activity and sperm morphology were assessed subjectively. Sperm motility and other kinetic parameters were objectively assessed using CASA (computer-assisted semen analysis). The semen diluted according to the treatments were submitted to the thermoresistance test, incubated at 37 ° C, and the sperm parameters analyzed at 0, 30, 60, 120 and 180 min. The average values of the treatments were compared with each other and between the times. There were no differences (P > 0.05) between treatments until the end of the test. Control and streptomycin-penicillin samples maintained sperm function for up to 180 min (with total motility of 24.3 ± 7.1% and 28 ± 8.7%, respectively). Gentamicin aliquots retained most parameters until the end of the incubation, except for membrane integrity and mitochondrial activity that declined (P < 0.05) at 180 min (53.1 ± 7.1% and 50.7 ± 6.2%, respectively) compared to 0 min (80.5 ± 4.7% and 86.3 ± 3.4%, respectively). In conclusion, a multiparametric thermoresistance test proved that Tris-based extenders used for collared peccary semen can be effectively supplemented by streptomycin-penicillin (2 mg/ml-2000 IU/ml) or gentamicin (70 µg/ml), especially during 180-min incubation at 37 °C.

Embryonic stem cells (ESCs) have proven to be a great in vitro model that faithfully recapitulates the events that occur during in vivo embryogenesis, making them a unique tool to study the cellular and molecular mechanisms that define tissue specification during embryonic development. Livestock ESCs are particularly attractive and have broad prospects including drug selection and human disease modeling, improvement of reproductive biotechniques and agriculture-related applications such as production of genetically modified animals. While mice and human ESCs have been established many years ago, no significant advances were made in livestock species until recently. Nowadays, livestock ESCs are available from cattle, pigs, sheep, horses and rabbits with different states of pluripotency. In this review, we summarize the current advances on livestock ESCs establishment and maintenance along with their present and future applications.

Reproductive biotechniques in the equine species have advanced in the last decade and horse breeders have started to question the possibilities of interfering in the determination of foal sex. The aim of the present study was to verify whether the variables mares and stallion's age, side of the ovary containing the preovulatory follicle, preovulatory follicle diameter, time between breeding and ovulation, and ovulation inducing hormones influence the sex of the foal. A total of 259 reproductive cycles of 160 mares and 22 Thoroughbred stallions were used. Statistical analysis was performed using R software, including Pearson's chi-square test and logistic regression. Of the total foals born, 136 were males (52.51%) and 123 were females (47.49%). In mares that ovulated with -24h after ovulation induction, 104 foals (54.74%) were males and 86 (45.26%) were females, while in mares that ovulated with +24h, 32 foals (46.38%) were males and 37 (53.62%) were females. Stallions up to 15 years old had 44.14% (n=49) females and those over 15 years had 49.66% (n=73) females. The simple logistic regression model showed that mares and stallions under 15 years old, mares with ovulation time less than 24 hours and treated with Deslorelin had a higher probability of having male foals, but the Pearson's chi-square test showed that foals gender were not influenced by the variables studied.

This study aimed to investigate the effect of including mouse feed with different concentrations (5, 10, or 20%) of Pereskia aculeata Miller (PAM) leaves on the morphology and development of preantral ovarian follicles and ovarian stromal cell density. The oral toxicity was performed using repeated dose toxicity assays subdivided into experiments of 30 days and 90 days of treatment. After the experiments, the ovaries of each animal were collected and submitted to classical histology. At 30 and 90 days, there was an equivalent percentage of normal, primordial, and developing follicles (P > 0.05) between PAM treatments compared to the control. Regarding the different stages of follicular development, after 90 days, there was a higher percentage (P < 0.05) of developing follicles only in the control group compared to day 30. The PAM 5% treatment was the only one that affected the cell density in the stroma after 90 days of treatment. Thus, we observed that supplementing the diet with P. aculeata did not pose any risk concerning animal consumption; specifically, there were no toxic reproductive effects observed from adding Pereskia aculeata Miller to the mouse diet.

Treating lactating sows with chorionic gonadotropins may allow controlling their post-weaning reproductive function, despite the occurrence of anestrous during lactation. This article reviews the potential effectiveness of treatment with both equine and human chorionic gonadotropins (eCG and hCG, respectively) during lactation on the control of estrus expression and ovulation in weaned sows. The use of 1,000 IU hCG at 24 and 48 h postpartum may induce ovulation in the treated sows, but the ovulation rate may be variable. Pregnancy rates may be improved with combined treatment after the second week of lactation with both chorionic gonadotropins: 1,500 IU eCG plus 500 - 1,000 hCG; or 1,000 IU eCG plus 1,000 IU hCG. Treatment with eCG (1,000 - 2,000 IU) at the end of lactation may result in acceptable estrus expression and ovulation rates, although with marginal benefit for pregnancy rates. The subsequent response to treatments with chorionic gonadotropins during lactation is likely influenced by the treatment period, the suckling frequency during lactation, and the boar exposure during the weaning-to-estrus interval. A better understanding of the efficiency of such steroid-free treatments is increasingly relevant due to the constraints of the use of steroid hormones in livestock reproductive management.

Histone deacetylase 9 (HDAC9) is a histone deacetylase (HDAC) subtype IIa protein that deacetylates histone 3 (H3), histone 4 (H4), and nonhistone proteins in vivo to alter chromosomal shape and regulate gene transcription. There have been few studies on the regulatory influence of the HDAC9 gene on the differentiation of chicken embryonic stem cells (cESCs) into male germ cells, and the significance of HDAC9 is still unknown. Therefore, we explored the specific role of HDAC9 during differentiation of the cESCs of Jilin Luhua chickens through inhibition or overexpression. In medium supplemented with 10^-5 mol/L retinoic acid (RA), cESCs were stimulated to develop into germ cells. HDAC9 and germline marker gene mRNA and protein levels were measured using qRT‒PCR and western blotting. During the differentiation of cESCs into male germ cells, overexpression of the HDAC9 gene greatly increased the mRNA and protein expression levels of the germline marker genes Stra8, Dazl, c-kit, and integrin ɑ6. The HDAC9 inhibitor TMP195 significantly decreased the mRNA and protein expression levels of the above markers. In summary, HDAC9 positively regulates the differentiation of cESCs.

In 2024, the Brazilian College of Animal Reproduction (CBRA in Portuguese) is proudly celebrating its golden 50^th anniversary. Founded in 1974, CBRA has had a very productive and challenging journey of five decades, achieving many important milestones that have established it as a major society and its journal as a major reference in the field of animal reproduction, both in Brazil and internationally. Coincidentally, the Animal Reproduction journal and the International Symposium on Animal Biology (ISABR), both created and sponsored by CBRA, are also celebrating their 20^th and 10^th anniversary and edition, respectively, this year. These remarkable events are being celebrated in the city of Fortaleza, Brazil, during the 10^th edition of ISABR. As someone who had the privilege of playing a leading role in the creation and establishment of both Animal Reproduction journal and ISABR, I am honored to describe here the favorable circumstances that led to these significant achievements. The crucial steps and combined efforts required to make these institutions successful were unconditionally supported by the CBRA. Additionally, significant global networking and scientific collaborations, both individual and collective, have been pivotal in advancing the science and connecting the scientific community, spanning both young and experienced members, for decades. Finally, I hope that this historical article will inspire future generations of scientists in the field to continue CBRA's journey and leadership, ensuring the growth of Animal Reproduction and ISABR advancement to even higher standards.

This study aimed to investigate the effect of temperature on gonadal differentiation, growth, survival, and sex ratio of Leporinus friderici reared at 25 °C or 29 °C from 50 to 240 days after eclosion (DAE) in a water recirculation system. A total of 110 fish at 50 DAE (6.7 ± 0.1 cm and 6.1 ± 0.3 g) were equally and randomly distributed in 10 boxes (90 L) (11 fish/box, 5 boxes/temperature). One fish from each experimental unit was randomly sampled at 50, 70, 90, 110, 130, 150, 170, 190, 210 and 240 DAE. Female gonadal differentiation started at 150 DAE (11.4 ± 0.0 cm and 16.4 ± 0.0 g) at 25 °C and at 170 DAE (10.7 ± 0.7 cm and 27.7 ± 8.5 g) at 29 ºC, while testes differentiation only occurred at 29 °C from 190 DAE (12.1 ± 0.0 cm and 38.0 ± 0.0 g). Of 50 fishes sampled in each condition, 17 (12 females and five males) and three (three females) displayed gonadal differentiation at 29 °C and 25 °C, respectively. Final biometric values at 29 °C were twice those obtained at 25 °C, reaching 13.9 ± 0.65 cm and 57.3 ± 10.12 g versus 11.2 ± 0.39 cm and 28.5 ± 2.95 g, respectively. While temperature clearly influenced gonadal differentiation and growth, it had inconclusive effects on sex ratio. The higher temperature (29 °C) has direct implications for the production of this species, as it accelerates growth without causing mortality.

In Experiment 1, PBMC were isolated from cows considered healthy or with SCE (n=6/group) on Days 0 (estrus) and 7 (diestrus) of a synchronized estrous cycle. In Experiment 2, on D21 (D0 was defined as the day of Fixed Timed Artificial Insemination (FTAI), cows were evaluated by ultrasonography to assess luteal blood perfusion and PBMC were isolated. On D32, cows were classified into: healthy pregnant (n=7), pregnant with SCE (n=4), healthy non-pregnant (n=8), and non-pregnant with SCE (n=10). Gene expression of ISGs (ISG15, OAS1, MX1 and IFI6) and proinflammatory cytokines (IL1-β, TNF-α and IFN-γ) were determined. Expression of ISG15, MX1, IFI6, TNF-α and IFN-γ did not differ between SCE and healthy cows and between Days 0 and 7. Expression of OAS1 and IL1-β were higher (P=0.02) on Day 7 than Day 0, regardlees of the SCE presence. In Exp.2, ISG15 abundance was 2.5-fold greater (P=0.0008), TNF-α was 2.2-fold greater (P=0.05), and IL1-β tended (P=0.06) to be 2.4-fold higher in pregnant than non-pregnant cows. Luteal blood perfusion was greater (P=0.01) in pregnant animals. In conclusion, OAS1 and IL1-β are transcripts upregulated in PBMC at diestrus, regardless of SCE occurrence. Proinflammatory cytokines are not affected by SCE occurrence, but IL1-β and TNF-α are upregulated in pregnant animals on D21 of pregnancy. ISG15 abundance is a good pregnancy predictor, regardless SCE presence.

During oocyte meiosis resumption, a coordinated program of transcript translation and decay machinery promotes a remodeling of mRNA stores, which determines the success of the acquisition of competence and early embryo development. We investigated levels of two genes related to mRNA translation (CPEB1 and CPEB4) and two related to mRNA degradation (CNOT7 and ZFP36L2) machinery and found ZFP36L2 downregulated in in vitro-matured bovine oocytes compared to in vivo counterparts. Thereafter, we tested the effects of a pre-IVM step with NPPC and a modified IVM with AREG on the modulation of members of mRNA translation and degradation pathways in cumulus cells and oocytes. Our data showed a massive upregulation of genes associated with translational and decay processes in cumulus cells, promoted by NPPC and AREG supplementation, up to 9h of IVM. The oocytes were less affected by NPPC and AREG, and even though ZFP36L2 transcript and protein levels were downregulated at 9 and 19h of IVM, only one (KDM4C) from the ten target genes evaluated was differently expressed in these treatments. These data suggest that cumulus cells are more prone to respond to NPPC and AREG supplementation in vitro, regarding translational and mRNA decay programs. Given the important nursing role of these cells, further studies could contribute to a better understanding of the impact of these modulators in maternal mRNA modulation and improve IVM outcomes.