The fertility rates of cryopreserved poultry semen are highly variable and not reliable for use in preservation of commercial genetic stocks. Our objective was to evaluate the cryosurvival of semen from 8 pedigreed layer lines at 2 different ages: the onset and end of commercial production. Semen from 160 roosters (20/line) was frozen individually with 11% glycerol at 6 and 12 mo of age. Glycer...

Effect of propylthiouracil (PTU)-induced hypothyroidism during the prepubertal period, at a dose of oneg per kg of the diet, on serum testosterone level and seminal characteristics of Fars indigenous chickens wasstudied. PTU was fed between 7th to 13th weeks of age and semen was collected at weekly intervals, starting at 21st week of age and continued for seven weeks. The effect of PTU treatmen...

An efficient method of transgene modulation in fertilized eggs has been developed that uses the Cre/loxP recombination system. Twelve transgenic mouse lines carrying a chicken beta-actin promoter-loxP-chloramphenicol acetyltransferase (CAT) gene-loxP-beta-galactosidase gene construct were produced. After selection of the line showing the highest expression of the CAT gene in a variety of tissue...

The endogenous peptides and small proteins present in chicken sperm were identified in the context of the characterization of a fertility-diagnostic method based on the use of ICM-MS (Intact Cell Matrix-Assisted Laser Desorption/Ionization Time-of-Flight Mass Spectrometry). The interpretation and description of these data can be found in a research article, "Intact cell MALDI-TOF MS on sperm: a...

OBJECTIVES The Streptomyces phage phiC31 integrase offers a sequence-specific method of transgenesis with a robust long-term gene expression. PhiC31 has been successfully developed in a variety of tissues and organs for purpose of in vivo gene therapy. The objective of the present experiment was to evaluate PhiC31-based site-specific transgenesis system for production of transgenic bovine embry...

The extracellular zona pellucida surrounds ovulated eggs and mediates gamete recognition that is essential for mammalian fertilization. Zonae matrices contain three (mouse) or four (human) glycoproteins (ZP1-4), but which protein binds sperm remains controversial. A defining characteristic of an essential zona ligand is sterility after genetic ablation. We have established transgenic mice expre...

The use of immunogenetic concepts in marine population research is rapidly expanding (Cushing 1962) and pertinent material on whales has been reviewed (Fujino, 1960). In the case of sperm whales, a "species-specific" antigen resembling the human B antigen has been found on their erythrocytes, and antibodies for the human ABO system occur variably in their serums. Chicken and rabbit antiserums p...

Aim: The present experiments were conducted (a) to evaluate the semen attributes of older Rhode Island Red (RIR) roosters and the inter-trait relationships, (b) to test sperm washing and storage duration suitable for gene transfer experiments. Materials and Methods: The semen characteristics of older RIR roosters were studied, and Pearson correlation analysis was done to demonstrate the inter-t...

We report initial studies on estrogen-mediated regulation of egg yolk protein synthesis in the rooster. Egg yolk proteins are normally synthesized as a large precursor, vitellogenin, in the liver of the laying hen; roosters synthesize vitellogenin only when treated with estrogen. Polysomal RNA from the liver of estrogen-treated roosters was translated in a reticulocyte cell-free system, and the...