Fertilization and development of the preimplantation embryo is under genetic control. The present goal was to test 434 single nucleotide polymorphisms (SNPs) for association with genetic variation in fertilization and early embryonic development. The approach was to produce embryos from 93 bulls using in vitro procedures (n = 3-6 replicates per bull) and relate cleavage rate (CR) and developmen...

The present study was undertaken to investigate the effect of various levels of vitamin B12 in Tris extender on semen quality of Dallagh rams following the cooling and freeze/thawing process. Semen was collected from six healthy and mature rams with an average body weight of 60.0 ± 5.0 Kg using an electro ejaculator. High quality samples were mixed and diluted in Tris extender supplemented with...

Cryopreservation of caudal epididymal spermatozoa is an effective technique to conserve genetic potentials of superior dogs when it is not possible to collect ejaculated spermatozoa. Although hen egg yolk is commonly supplemented into the semen extender, active substances within the egg yolk which protect sperm against cryoinjury remain to be discovered. Among its compositions, low-density lipo...

The diverse structures of polyketide natural products are reflected by the equally diverse polyketide biosynthetic enzymes, namely polyketide synthases (PKSs). Three major classes of PKSs are known-noniterative type I PKSs, iterative type II PKSs and acyl carrier protein-independent type III PKSs, each of which consists of additional variants. One such variant is the noniterative type I PKS in ...

The aim of the study was to evaluate the effect of the addition of 20% bull seminal plasma to semen extenders on post-thaw sperm motility, morphology, and fertility. Two Merino rams at 3-5 years of age, 43 ewes, and one Holstein bull were used. Fourteen ejaculates were collected by the use of an artificial vagina, twice a day, at 60 min interval. Six semen ejaculates were extended with Tris-egg...

FK506 (tacrolimus) is a secondary metabolite with a potent immunosuppressive activity, currently registered for use as immunosuppressant after organ transplantation. FK506 and FK520 are biogenetically related natural products that are synthesized by combined polyketide synthase/nonribosomal peptide synthetase systems. The entire gene cluster for biosynthesis of FK520 from Streptomyces hygroscop...

This study was conducted to examine if L-carnitine supplementation in the Tris-egg-yolk extender can improve the motility characteristics, membrane integrity, and in vitro fertilization potential after cryopreservation of ejaculated bovine spermatozoa. It was carried out on January to May 2013 at the University of Wisconsin-Madison. L-carnitine at final concentrations of 0.5, 1, 10, and 30mM we...

Camels represent part of the Arab heritage. The interest in developing assisted reproductive technologies and cryobanking for the conservation of animal genetic resources has recently increased. However, semen collections in camelids present many problems as sitting position during copulation, slow ejaculation and difficult animal handling. In these cases epididymal sperm from slaughtered or re...

The aim of this study was investigation of various levels of vitamin E in Tris extender on semen characteristics of Ghezel rams in pre and post freezing conditions. Semen was collected from six healthy and mature rams with average 55±5 Kg body weight by electro ejaculator. High quality samples were mixed and diluted in Tris extender after apply different concentration of vitamin E. Treatments w...

Mammalian spermatozoa experience osmotic stress when the glycerol is added to the cells before freezing and removal from the cells after thawing. To minimize osmotic damage, alternative cryoprotectants, having lower molecular weights and greater membrane permeability than glycerol, were evaluated to determine their effectiveness for cryopreserving bull spermatozoa. The primary goal of this stud...