Estrus Synchronization and Artificial Insemination in Goats during Low Breeding Season-A Preliminary Study

A pilot project was initiated to introduce artificial insemination (AI) in goats at farmer level with chilled semen. Does (n=18) were synchronized with progesterone impregnated vaginal sponges (60 mg Medroxyprogesterone acetate; MAP) for 11 days. At 48 hrs prior to removal of the sponges, intramuscular injection of 400 IU equine chorionic gonadotropin (eCG) and cloprostenol (0.075 mg) was given. Fixed time vaginal insemination (43-45 hrs after sponge removal) was done twice (at 12 hrs interval) in 17 does with chilled Beetal buck semen (4°C) extended with Tris-citric acid (TCA) or skimmed milk (SM) based extender (75 x 106 sperm/ml). Pregnancy test was performed at 45 days post insemination through ultrasonography. An overall 94.5% (17/18) of does showed heat signs and 78% of them were detected in heat between 12 - 24 hrs after sponge removal. An overall 29.4% (5/17) pregnancy rate was recorded. Higher pregnancy rate (44.4%) was obtained in does inseminated with SM extended semen as compared to 12.5% for TCA extended semen. Results were encouraging in the sense that to the best of our knowledge it was the first report of kidding through AI in heat induced does in Pakistan. Moreover, it indicated the feasibility of using synchronization and fixed time AI during low breeding season to enhance the reproductive efficiency in local goats

SIRT3 Regulation Under Cellular Stress: Making Sense of the Ups and Downs

Sirtuin 3 (SIRT3) is an NAD+ dependent deacetylase that resides primarily in mitochondria and functions to maintain mitochondrial homeostasis under stress. SIRT3 expression has been observed to change under a number of different stresses in multiple tissues and model systems. Inconsistencies in the literature with regards to how and when SIRT3 protein levels change indicates that the mechanism of SIRT3 regulation is multi-faceted. Alterations in SIRT3 have been observed in experimental models of cellular stress, however, the effect these changes have on mitochondrial health remain unknown. Neurons are highly dependent on proper mitochondrial function for their survival. SIRT3 dynamics and function have been studied using models of genotoxic, metabolic, and oxidative stresses, although it remains unclear how SIRT3 is being regulated under these conditions. A closer look into SIRT3 regulation under stress conditions in various model systems will help incorporate the many SIRT3 regulatory mechanisms at play in disease states. In this review, we describe the observations that have been made about SIRT3 protein modulation under basic stress conditions. We then point out consistencies and contradictions in these observations and what they mean. Lastly, we present the observations made in the complicated neuronal stress of stroke. We hope that this review will help consolidate the ambiguous SIRT3 literature and provide a framework for investigation of SIRT3 regulation during stress response

EFFECT OF NON-ENZYMATIC ANTIOXIDANTS IN EXTENDER ON POST-THAW QUALITY OF BUFFALO (BUBALUS BUBALIS) BULL SPERMATOZOA

The objective of the present study was to determine the effect of non-enzymatic antioxidants (vitamin C or E) in tris-citric acid buffer (TCA) on post-thaw quality of buffalo (Bubalus bubalis) bull spermatozoa. Split pooled buffalo bull ejaculates were diluted in TCA egg yolk glycerol extender containing either vitamin C (TCAC), vitamin E (TCAE) or without antioxidant (TCAN) at 37°C. Extended semen was cooled to 4C in 2 h and equilibrated for 4 h at 4C. Cooled semen was then filled in 0.5 ml straws at 4C and frozen in programmable cell freezer. Thawing of semen was performed at 37°C for 30 seconds. Sperm motility, plasma membrane integrity and sperm morphology (acrosome integrity, head, mid-piece and tail abnormalities) of each semen sample were evaluated. Percentage of post-thaw spermatozoal motility assessed visually at 0 and 6 h and the post-thaw percentage of spermatozoa with intact plasma membranes at 0 h were higher (P<0.05) with TCAC and TCAE compared to control. However, the differences in both these parameters between the former two groups was non significant. The post-thaw percentage of spermatozoa with normal acrosomes was higher (P<0.05) in TCAE extender than control. Mean sperm abnormalities in samples cryopreserved with extender having TCAC, TCAE or TCAN were similar (P>0.05). In conclusion, non-enzymatic antioxidants, particularly vitamin E, in the tris citric acid extender may improve the quality of frozen-thawed buffalo bull spermatozoa

EFFECT OF REDUCING SPERM NUMBERS PER INSEMINATION DOSE ON FERTILITY OF CRYOPRESERVED BUFFALO BULL SEMEN

The objective of this study was to evaluate the effect of reducing sperm numbers per insemination dose on fertility of cryopreserved buffalo bull semen. For this purpose, semen was collected at weekly intervals from a Nili-Ravi buffalo bull (Bubalus bubalis) using an artificial vagina in two batches. The ejaculates were split-sampled and diluted at 37°C with tris-citric acid extender having 15x106 or 30x106 motile spermatozoa/0.5 ml. After dilution, the semen was cooled to 4C, equilibrated for 4 hours, packaged in 0.5 ml straws and frozen in programmable cell freezer. Fertility test based on 75-days first service pregnancy rate was determined under field conditions. A total of 500 buffaloes were inseminated with frozen semen and out of these 431 could be followed, 209 for semen straws packaged with 15x106 spermatozoa/straw and 222 for doses filled with 30x106 spermatozoa/straw. The inseminations were performed in two batches and each batch was spread over a period of three months. The fertility rate for sperm concentration of 15x106 spermatozoa/0.5 ml vs. 30x106 spermatozoa/0.5 ml (49.28 vs. 56.75%) was similar (P>0.05). The fertility rates were also similar (P>0.05) in the first and second batch of inseminations performed with 15x106 or 30x106 spermatozoa/0.5 ml straw of cryopreserved semen. In conclusion, reduction of sperm number from 30x106 to 15x106 spermatozoa/0.5 ml dose of insemination did not affect fertility of cryopreserved buffalo bull semen

Nitric Oxide: Physiological Functions, Delivery, and Biomedical Applications

Nitric oxide (NO) is a gaseous molecule that has a central role in signaling pathways involved in numerous physiological processes (e.g., vasodilation, neurotransmission, inflammation, apoptosis, and tumor growth). Due to its gaseous form, NO has a short half-life, and its physiology role is concentration dependent, often restricting its function to a target site. Providing NO from an external source is beneficial in promoting cellular functions and treatment of different pathological conditions. Hence, the multifaceted role of NO in physiology and pathology has garnered massive interest in developing strategies to deliver exogenous NO for the treatment of various regenerative and biomedical complexities. NO-releasing platforms or donors capable of delivering NO in a controlled and sustained manner to target tissues or organs have advanced in the past few decades. This review article discusses in detail the generation of NO via the enzymatic functions of NO synthase as well as from NO donors and the multiple biological and pathological processes that NO modulates. The methods for incorporating of NO donors into diverse biomaterials including physical, chemical, or supramolecular techniques are summarized. Then, these NO-releasing platforms are highlighted in terms of advancing treatment strategies for various medical problems

Fertilization capacity with rainbow trout DNA-damaged sperm and embryo developmental success

Mammalian spermatozoa undergo a strong selection process along the female tract to guarantee fertilization by good quality cells, but risks of fertilization with DNA-damaged spermatozoa have been reported. In contrast, most external fertilizers such as fish seem to have weaker selection procedures. This fact, together with their high prolificacy and external embryo development, indicates that fish could be useful for the study of the effects of sperm DNA damage on embryo development. We cryopreserved sperm from rainbow trout using egg yolk and low-density lipoprotein as additives to promote different rates of DNA damage. DNA fragmentation and oxidization were analyzed using comet assay with and without digestion with restriction enzymes, and fertilization trials were performed. Some embryo batches were treated with 3-aminobenzamide (3AB) to inhibit DNA repair by the poly (ADP-ribose) polymerase, which is an enzyme of the base excision repair pathway. Results showed that all the spermatozoa cryopreserved with egg yolk carried more than 10% fragmented DNA, maintaining fertilization rates of 61.1+/-2.3 but a high rate of abortions, especially during gastrulation, and only 14.5+/-4.4 hatching success. Furthermore, after 3AB treatment, hatching dropped to 3.2+/-2.2, showing that at least 10% DNA fragmentation was repaired. We conclude that trout sperm maintains its ability to fertilize in spite of having DNA damage, but that embryo survival is affected. Damage is partially repaired by the oocyte during the first cleavage. Important advantages of using rainbow trout for the study of processes related to DNA damage and repair during development have been reported. Reproduction (2010) 139 989-997Junta de Castilla y Leon (Spain) [LE007A06]; University of Leoninfo:eu-repo/semantics/publishedVersio

Autologous neutralizing antibody responses to an HIV envelope glycan hole are not easily broadened in rabbits

Extensive studies with subtype A BG505-derived HIV Env immunogens have revealed that the dominant autologous neutralizing epitope in rabbits is located in an exposed region of the heavily glycosylated trimer that lacks potential N-linked glycosylation sites at positions 230, 241, and 289. The Env derived from B41, a subtype B virus, shares a glycan hole centered on positions 230 and 289. To test whether broader neutralization to the common glycan hole can be achieved, we immunized rabbits with B41 SOSIP alone, as well as B41 and BG505 co-immunization. We isolated autologous neutralizing antibodies (nAbs) and described their structure in complex with the B41 Env. Our data suggest that distinct autologous nAb lineages are induced by BG505 and B41 immunogens, even when both were administered together. In contrast to previously described BG505 glycan hole antibodies, the B41-specific nAbs accommodate the >97% conserved N241 glycan, which is present in B41. Single particle cryo-electron microscopy studies confirmed that B41 and BG505-specific nAbs bind to overlapping glycan hole epitopes. We then used our high-resolution data to guide mutations in the BG505 glycan hole epitope in an attempt to broaden the reactivity of a B41-specific nAb, but only recovered partial binding. Our data demonstrate that lack of cross-reactivity in glycan hole antibodies is due to amino acid differences within the epitope and our attempts to rationally design cross-reactive trimers resulted in only limited success. Thus, even for the immunodominant glycan hole shared between BG505 and B41 the prospect of designing prime-boost immunogens remains difficult