Documentation of Genetic Diversity by Insulin-Like Growth Factor۱ Receptor (Exon۲) Gene for Fallow Deer (Dama dama) in Iraq

Insulin-Like Growth Factor۱ Receptor (Exon۲) (IGF۱R) gene plays a vital role in physiological impacts, such as growth, development, reproduction, and metabolism. A significant difference was noted between the IGR۱R (exon ۲) gene and the body weight of Dama dama. In addition, the heterozygosity pattern (AB) was significantly higher than the other pattern (AA). There are three single nucleotide polymorphisms (SNPs; ۱۴۴G˃C, ۱۴۷A˃G, and ۲۱۰A˃C) within the IGF-۱R (exon ۲) locus. The statistical analyses indicated the presence of three different haplotypes (GAA, CAA, and GGC). The analysis of relative frequencies indicated that the most frequent haplotype in the studied Dama dama population was Hap۳ (GGC) (۴۳.۴۷۸۲%) out of the three observed haplotypes. The results of SSCP-PCR revealed the variability of the target gene between the genotype frequencies in Fallow deer (Dama dama) with a high level of significance (P≤۰.۰۱) with two patterns (AA and AB) and an absence of BB pattern. The allele frequency of AA record a high level (۷۱.۷۴%) than the other genotype (AB) (۲۸.۲۶%), with a high-frequency level of the A allele (۰.۸۶) than the B allele (۰.۱۴). In current findings, SSCP genotyped in the Dama dama DNA observed an estimated ۷۲% monomorphic loci and ۲۸% polymorphic loci approximately. Hardy Weinberg equilibrium test (HW) was applied to the SSCP-PCR data matrix, and the statistical test was based on a chi-square (χ۲) test. Chi-square was (۵۵.۹۲۸%) with a highly significant level (P≤۰.۰۱) recorded in the present study. As related to AA and AB genotypes mean,  a significant difference (P≤۰.۰۵) was noted between IGF۱R (exon ۲) gene with a body weight of Dama dama, as well as the heterozygosity pattern (AB), was significantly (P≤۰.۰۵) higher than the other pattern (AA) (۳۰.۳۴±۳.۰۱kg versus ۲۴.۸۵±۱.۹۴kg), respectively. A significant impact (P≤۰.۰۵) between IGF۱R (exon۲) polymorphism and heart girth was founded to be related to the AB pattern (heterozygous) (۷۶.۹۲ ± ۳.۲۰ cm), whereas the lower value was related to the AA pattern (۷۱.۳۳ ± ۲.۴۹ cm). No significant differences in effects were shown in relation to body length and height at the shoulder. The present study is also interested in genetic characterization by calculating (Ne) as a tool for genetic diversity. Therefore, the number of alleles detected (Na) indicates that two alleles only were unique in the population of the study, with (۱.۳۲۰۴) being the number of efficient alleles (Ne). Moreover, Shannon's Information index was recorded at ۰.۴۰۷۳. The observed homozygosity (O.Hom.) and heterozygosity (HO) were (۰.۷۱۷۴ and ۰.۲۸۲۶), respectively. The values of expected homozygosity (E.Hom.) and heterozygosity (HE) were ۰.۷۵۴۷ and ۰.۲۴۵۳, respectively. The genetic diversity of Nei was ۰.۲۴۲۷. The results showed an unexpected influx of IGF۱R diversity measured by Fis and recorded the value (- ۰.۱۶۴۶). In this sense, the results of the current study may be considered an approximation to the total genetic diversity of the population of Dama dama in Iraq, but the information obtained is relevant to proposing the strategies of conservation for the genetic diversity observed.

Keywords:

Fallow deer (Dama dama) , IGF۱R (exon۲) gene , SNPs , SSCP-PCR , Shannon's index , Gene flow