Detection of genetic variation in sample of Iranian proofed Holstein cattle by using microsatellite marker

This study describes genetic variation among samples of Iranian Holstein cattle (Bos taurus) by using microsatellite markers. Semen samples of individuals were taken followed by DNA extraction. A panel of13 microsatellites was used for evaluation of 13 loci in 68 Holstein proofed bulls. Mean value for allele per locus detected is 6.615, ranging from 10 (SPS115) to 4 (ETH3). All the microsatellite DNA markers showed high polymorphism and displayed a relatively high level of genetic variation as estimated by allelic diversity and heterozygosity. Estimated heterozygosities ranged from 1.000 (BM2113, TGLA122, TGLA126, ETH3, MGTG4B, SPS115, TGLA227 and INRAO23) to 0.633 (SPS113) with mean value of 0.946. All the loci showed deviation from Hardy- Weinberg equilibrium (p < 0.001), polymorphism information content (PIC) calculated for each marker exceeded 0.6 and the mean value of Shannon information index was estimated to be 1.606. Obtained results showing heterozygousity can be useful for the development of breeding strategies for genetic improvement in Iranian Holstein cattle.Keywords: Genetic variability, polymorphism, microsatellite loci, Bos taurus, Iranian Holstein cattle, DN

Determination of maturation and spawning season of Otolithes ruber (Croaker Fish) in Khuzestan coastal water, Iran

In this study, the stage of gonadal development, type and season of spawning of Otolithes ruber in the North West of Persian Gulf were identified. O.ruber maturation and spawning were studied by macroscopic, microscopic, and histologic observation of gonads which obtained from October 1996 to September 1997 in Khouzestan coasts. In the histologic sections of gonad tissue, stages I to VII of gonadal development were distinguished. Post Spawning follicules were observed only in stages VI and VII (in April and May). Atretic ovums were also clearly observed in these stages. Frequency of Ovum diameter distribution in stages II to V is a unimodal which proves that annual maturation of ovums and spawning of this species are simultaneous. The highest level of GSI was observed in March and also higher stages 01' gonadal maturation were observed in March and April. Fast drop in GSI in May and within occurrence of both spawning and spent individuals in only two months of the year shows the relatively short spawning season is spring (April-May). Sexual maturation of females occured after the males and its first length in females was 216 mm

Genetic variation among pelt sheep population using microsatellite markers

Genetic variation in three Iranian pelt sheep breeds namely: Gray Shiraz, Zandi and Karakul were investigated using fifteen microsatellite loci. Genomic DNA was extracted from 360 blood samples by extraction kits and salting-out procedure with some modifications. The total number of alleles ranged from 6 to12 in loci. The fifteen tested loci were all polymorphic in the three breeds. The average direct count of heterozygosity overall loci in each tested breed was more than the expected heterozygosity. Tests of genotype frequencies for deviation from the Hardy-Weinberg equilibrium (HWE) were performed at each locus of overall breeds and revealed significant departure from HWE (P < 0.001) due to heterozygote excess. Polymorphism information content value in Gray Shiraz, Zandi and Karakul were 0.815, 0.808 and 0.808, respectively. Rate of inbreeding within the three breeds was not noticeable (global Fis = - 0.19). Low genetic differentiation was detected by estimation of Fst index between all pairs of breeds. Results showed that high level of genetic diversity was observed in pelt sheep. The phylogenetic tree based on Nei distances were drown using the neighbor-joining (NJ) and unweighted pair-group method using an arithmetic average (UPGMA). With both methods, Gray Shiraz and Karakul sheep populations were located together at one cluster and Zandi sheep population at another. The results can be useful in the development of breeding strategy for genetic improvement of pelt sheep in Iran. © 2010 Academic Journals

Studying molecular 2 species econimic shrimps (P. merguiensis, P. indicus) Northern coast of the Persian Gulf and Oman sea using microsatelitte markers to separating and identificating of their possible populations

This study focuses on molecular investigation of two commercial shrimp species of penaeus family namely as : P. merguiensis and P. indicus in order to find and introduce the genetic differentiations and also probable genotypes for monitoring and managing the genetic resources of populations in three major catch areas in the Persian Gulf and the Oman Sea. Only five out of the eight primers for P. merguiensis and four out of the eight primers for P. indicus produced good amplified PCR products with fixed annealing temperature. The rest of the primers were either not easily amplified or produced nonspecific bands. Seven and six alleles were found to be unique to each of the three populations in P.merguiensis and and two populations of P. indicus respectively. Occurrences of heterozygosity deficiency were found at most loci. These heterozygosity deficiencies in observed heterozygosity in compare to expected heterozygosity may be due to inbreeding, genetic drift and consequences of illegal overharvesting of P. merguiensis and P. indicus in the studied areas as well. Deviation from HWE in both studied species was significant in most microsatellite loci (P <0.001). We observed deviation from HWE in most loci with hetrozygosity deficits. The genetic variation results showed that the pairwise Fst values were significant between populations in both species. The assignment test for P. merguiensis revealed high gene flow between Hormoz and Jask and restricted genetic flow between Guatr and Hormoz populations .We observed high gene flow between Hormoz and Jask populations for P. indicus. It seems that the changes in immigration patterns of populations between Hormoz, Jask and Guatr areas in both species are depend on the influence of Persian Gulf currents or the life cycle of studied species. Alternatively, the presence of ecological barriers such as mangrove forests may result in restricted genetic flow between Guatr and both Hormoz and Jask populations

Evaluation of Parentage Test in some of Holstein Cattle Using Fluorescent Labeled Microsatellite Markers

In order to evaluate paternity test using microsatellite markers, a small sample of Iranian Holstein cattle population including 8 unknown individuals without any given prior knowledge on their genetic relationships were tested using 12 microsatellite loci recommended by International Society of Animal Genetics (ISAG). They were genotyped by a multiplex PCR set consisted all 12 fluorescently labeled primer pairs. Allele and genotype frequencies were estimated and simulated by CERVUS 2.0 software for paternity analysis. Using this software parentage test and relationship between samples have been determined and confirmed by sample’s provider. Paternity relationship including one or two parents for an offspring and also repeated samples were observed. The average expected heterozygosity of 11 analyzed loci and the mean value for PIC was 0.72 and 0.631 respectively. Except TGLA53 locus that was excluded from further analyses due to low quality of alleles and genotype detection, total exclusion probability of 11 loci showed that the paternity test using microsatellite loci mentioned here can be successfully implicated in large scale in Holstein dairy cattle population in Iran