Genetic and phenotypic parameters for lamb growth traits were estimated for the Shal sheep used as animal model. Data on lamb growth performance were extracted from available performance records at the Shal sheep Station in Qazvin, Iran. Studied traits were the body weight of lambs at birth, at three months of age as weaning weight, the six months weight, nine months weight, yearling weight, average daily gain from birth to weaning and Kleiber ratio from birth to weaning. Significant random effects for each trait were determined by fitting additive direct genetic effects, additive maternal effects, the covariance between additive direct and additive maternal effects, maternal permanent environmental and maternal temporary environmental (common litter) effects of twelve animal models. Univariate analyses were carried out under the most appropriate model, determined by the Akaike information criterion test. Direct heritability estimates for birth weight, weaning weight, average daily gain, Kleiber ratio, six months weight, nine months weight and yearling weight were 0.13, 0.19, 0.18, 0.05, 0.16, 0.18 and 0.19, respectively. Maternal additive genetic effects were fitted only for birth weight and weaning weight. Corresponding estimates of 0.12 and 0.10 were obtained for maternal heritability of birth weight and weaning weight, respectively. Maternal permanent environmental effects have low contribution to the expression of Kleiber ratio and lead to estimates of 0.06 and 0.06 for permanent maternal environmental variance as a proportion of phenotypic variance (c 2 ) of these traits, respectively. All pre-weaning traits, except Kleiber ratio, were affected by litter effects. The magnitude of ratio of common litter variance to phenotypic variance (l 2 ) was 0.05, 0.12 and 0.14 for birth weight, weaning weight and average daily gain, respectively. Direct genetic correlations were positive and ranged from 0.09 for Kleiber ratio-yearling weight to 0.80 for weaning weight-average daily gain. Phenotypic correlations ranged from 0.18 for Kleiber ratio-yearling weight to 0.87 for weaning weight-average daily gain.

The main objectives of this study were to estimate genetic and phenotypic parameters for growth traits and prolificacy in the Raeini Cashmere goat. Traits included, birth weight (BWT), weaning weight (WWT), 6-month weight (6WT), 9-month weight (9WT), 12-month weight (12WT), average daily gain from birth to weaning (ADG1), average daily gain from weaning to 6WT (ADG2), average daily gain from 6WT to 12WT (ADG3), survival rate (SR), litter size at birth (LSB) and litter size at weaning (LSW) and total litter weight at birth (LWB). Data were collected over a period of 28 years (1982-2009) at the experimental breeding station of Raeini goat, southeast of Iran. Genetic parameters were estimated with univariate models using restricted maximum likelihood (REML) procedures. In addition to an animal model, sire and threshold models, using a logit link function, were used for analyses of SR. Age of dam, birth of type, sex and of kidding had significant influence (p < 0.05 or 0.01) all the traits. Direct heritability estimates were low for prolificacy traits (0.04 ± 0.01 for LSB, 0.09 ± 0.02 for LSW, 0.16 ± 0.02 for LWB and 0.05 ± 0.02 for SR) and average daily gain (0.12 ± 0.03 for ADG1, 0.08 ± 0.02 for ADG2, and 0.07 ± 0.03 for ADG3) to moderate for production traits (0.22 ± 0.02 for BWT, 0.25 ± 0.02 for WWT, 0.29 ± 0.04 for 6WT, 0.30 ± 0.02 for 9WT, 0.32 ± 0.05 for 12WT). The estimates for the maternal additive genetic variance ratios were lower than direct heritability for BWT (0.17 ± 0.03) and WWT (0.07 ± 0.02).

Screening the fertile ewes from national herds to detect the major genes for prolificacy is an effective way to create the fertile flocks. Growth differentiation factor (GDF) 9 is a member of the transforming growth factor β superfamily that is essential for folliculogenesis and female fertility. The aim of this study was to detect single nucleotide polymorphisms (SNPs) in exon 2 of GDF9 gene in Kermani sheep breed using PCR-SSCP. Genomic DNA was extracted from whole blood of collected samples using salting-out method. Whole exon 2 of GDF9 gene was amplified (634 bp and 647 bp fragments) using designed specific primers. The single stranded conformation polymorphism (SSCP) patterns of PCR products were studied using electrophoresis on acrylamide gel and silver-nitrate staining method. Finally, 4 banding patterns for the first primer pair and 4 banding patterns for the second primer pair were obtained. Also, indices of population genetic per SNP were calculated using Gen Alex 6.41 software. The sequencing results showed the presence of 3 mutations (SNP) (443, 477 and 721 positions) in the studied population.

Purpose Spermatogonial stem cells are affected by the interactions of extrinsic signals produced by components of the microenvironment niche, in addition to the chemical and physical properties of the extracellular matrix. Therefore, this study was initiated to assess the interaction of these cells on a synthetic nanofibrillar extracellular matrix that mimicked the geometry and nanotopography of the basement membrane for cellular growth. Methods This study has used a variety of experimental approaches to investigate the interaction of mouse neonatalderived spermatogonial stem-like cells on a synthetic random oriented three-dimensional nanofibrillar matrix composed of electrospun polyamide nanofibers (Ultra-Web™).Results Spermatogonial stem-like cell colonies were characterized by their ability to express α6-integrin, Thy-1, PLZF, and β1-integrin. After culture of cells on the nanofibrillar surfaces for 7 days, the number of colonies, the number of cells in each colony, and the average area of colonies were increased (P<0.05). However, the expression difference of related markers in both groups was not significant. A significantly higher proliferation and survival was observed in the nanofibrillar group (P<0.05). After transplantation into the testes of busulfan-treated adult mice, spermatogonial stem-like cell colonies that were cultured on the nanofibrillar surface demonstrated functionality, as verified by their ability to migrate to the seminiferous basal membrane, where they produced additional colonies. Conclusions These results have suggested that electrospun nanofibrillar surfaces could provide a more favorable microenvironment for in vitro short term culture of spermatogonial stem-like cell colonies.

Genetic parameters and genetic trends for birth weight (BW), weaning weight (WW), 6-month weight (6MW), and yearling weight (YW) traits were estimated by using records of 5,634 Makooei lambs, descendants of 289 sires and 1,726 dams, born between 1996 and 2009 at the Makooei sheep breeding station, West Azerbaijan, Iran. The (co)variance components were estimated with different animal models using a restricted maximum likelihood procedure and the most appropriate model for each trait was determined by Akaike's Information Criterion. Breeding values of animals were predicted with best linear unbiased prediction methodology under multi-trait animal models and genetic trends were estimated by regression mean breeding values on birth year. The most appropriate model for BW was a model including direct and maternal genetic effects, regardless of their covariance. The model for WW and 6MW included direct additive genetic effects. The model for YW included direct genetic effects only. Direct heritabilities based on the best model were estimated 0.15 ± 0.04, 0.16 ± 0.03, 0.21 ± 0.04, and 0.22 ± 0.06 for BW, WW, 6MW, and YW, respectively, and maternal heritability obtained 0.08 ± 0.02 for BW. Genetic correlations among the traits were positive and varied from 0.28 for BW-YW to 0.66 for BW-WW and phenotypic correlations were generally lower than the genetic correlations. Genetic trends were 8.1 ± 2, 67.4 ± 5, 38.7 ± 4, and 47.6 ± 6 g per year for BW, WW, 6MW, and YW, respectively.