Genetic polymorphism of plastid DNA in Tunisian date-palm germplasm (Phoenix dactylifera L.) detected with PCR-RFLP

Fifteen plastid fragments were amplified from a set of Tunisian date-palm accessions by PCR with consensus primers and analysed by RFLP. Polymorphic DNA bands were obtained as reliable molecular markers to estimate genetic distances among the accessions and to examine their phylogenetic relationships. The ctDNA PCR-RFLP method permitted the identification of two haplotypes that differ in the presence or absence of the HinfI restriction site. Phenetic groups composed of cultivars clustered together but does not constitute monophyletic groups. This typology agrees with the haplotypes' organization and provides a common genetic background within the implied varieties.     

基于mtDNA控制区新单倍型的斑背大尾莺种群遗传结构分析

采用非损伤DNA分析技术,在上海崇明岛自然保护区和辽宁双台河口自然保护区斑背大尾莺(Lo-custella pryeri)种群样本中检测出15个新的mtDNA控制区单倍型。结合已发表的数据进行综合分析,结果表明:在崇明岛自然保护区的种群与江西南矶山、辽宁双台河口、黑龙江扎龙地理种群间没有显著的遗传差异,该结果显示出上海崇明岛种群与其他3个地理种群的巢形相异在遗传学上缺乏关联。此外,双台河口新定义的3个单倍型与南矶山、双台河口、扎龙地区的单倍型以及双台河口以往发现的单倍型发生了明显分化,其分支间遗传距离显著大于各栖息地种群(约10倍)。这暗示了双台河口分布的斑背大尾莺种群部分发生了分化,或者后分化出的进化支(W,R)属于斑背大尾莺指名亚种或新亚种。     

Chloroplast DNA study in sweet cherry cultivars (Prunus avium L.) using PCR-RFLP method

The chloroplast DNA of 96 sweet cherry cultivars (Prunus avium L.) and five cultivars of sour cherry (P. cerasus L.) were analysed to reveal their haplotypes using PCR-RFLP (Polymerase Chain Reaction - Restriction Fragment Length Polymorphism) method. The main advantages of the PCR-RFLP technique are: resolutive, time and cost effective and reproducible. Approximately 9.6% of the chloroplast genome was analysed, using six universal primer pairs and two restriction enzymes. All the mutations detected were insertion-deletions, ranging between 5–30 bp. The combination of all the mutations resulted in three haplotypes (H1, H2 and H3) in the 96 sweet cherry cultivars and a single haplotype (H4) in the five cultivars of sour cherry. The cpDNA polymorphism determined by PCR-RFLP markers helped to understand the maternal inheritance of chloroplast genome in sweet cherry, clearly distinguished the sour from the sweet cherry, and supported that P. avium is not the maternal species of P. cerasus.     

Use of chloroplast microsatellite markers as a tool to elucidate polymorphism,classification and origin of Tunisian grapevines

Chloroplast microsatellite markers were used in this study to genotype 43 grapevines accessions grown in Tunisia. Size variation was observed for the three cpSSR loci, both in the sample of cultivars and in wild accessions. The seven alleles observed in the sample of cultivars for the three loci are present in wild accessions except that their distribution is different. Levels of genetic diversity obtained for the Tunisian grapevines either in wild or cultivated gene pools are high and comparable with values obtained with other studied samples of Vitis vinifera. The distribution of haplotypes within the two samples is differential. Indeed, the chlorotype A is most abundant in the wild sample, whereas the chlorotype C is majority in the sample of cultivars. Haplotypes frequencies for cultivated grapevine distinguish haplotypes B and C as the most frequent (28% and 44% respectively) and haplotypes A and D as the least frequent (16% and 12% respectively). For wild grapevines, the seven alleles combined in three haplotypes, A, C and D. The haplotype A is the most frequent (44%) in the analyzed sample of wild accessions while haplotypes C and D show a frequency of 28%. Chlorotype distribution in Tunisian cultivars is comparable with that of cultivars in the Eastern Region representing the primary centre of domestication of the species. These results agree with the higher relevance of table grape cultivars in Tunisian viticulture and support an oriental origin of a large part of autochthons cultivars. Our results agree with other studies based in nuclear and chloroplast microsatellite markers and suggest independent domestication events for V. vinifera L. species.     

Association of endothelial nitric oxide synthase gene rs7830 and rs3918188 polymorphisms with essential hypertension in Kazakh of Xinjiang region

AIM: To investigate the correlation between endothelial nitric oxide synthase (eNOS) rs7830 and rs3918188 locus polymorphisms and essential hypertension (EH) in the Kazakh of Xinjiang region. METHODS: Epidemiological case-control study was conducted. DNA was extracted by classic phenol-chloroform method, PCR amplification and purification. The rs7830 and rs3918188 of eNOS gene in 363 EH patients (EH group) and 370 normotensive controls (NT group) in the Kazakh of Xinjiang region were genotyped by the technique of SNaPshot single nucleotide polymorphism genotyping. The plasma levels of fasting blood glucose, uric acid, cholesterol and triglyceride were measured by biochemical methods. Determination of body mass index and waist-hip ratio was also conducted. RESULTS: Age (P<0.01), body mass index (P<0.01), triglyceride (P<0.01), low-density lipoprotein (P<0.05) and apolipoprotein A1/B (P<0.05) were the independent factors for EH in the Kazakh of Xinjiang region. No difference of eNOS gene rs7830 and rs3918188 loci in the genotype frequency and the allele frequency distribution between EH patients and normotensive controls in the Kazakh of Xinjiang region was observed (P>0.05). The frequency distribution of CA, CC, AC and AA haplotypes from eNOS gene rs7830 and rs3918188 loci between EH group and NT group also had no difference in the Kazakh of Xinjiang region (P>0.05). CONCLUSION: Age, body mass index and triglyceride are the independent risk factors, while low-density lipoprotein and apolipoprotein A1/B are the independent protective factors for EH in the Kazakh of Xinjiang region. The polymorphisms of eNOS gene rs3918188 and rs7830 loci are not related to EH in the Kazakh of Xinjiang region.     

Association between melanocortin 4 receptor (MC4R) gene haplotypes and carcass and production traits in Italian Large White pigs evaluated with a selective genotyping approach

Melanocortin 4 receptor (MC4R) plays a key role in controlling energy homeostasis. Several studies have already reported effects on production traits of polymorphisms identified in the porcine MC4R gene. In this study we analysed data on 6 MC4R polymorphisms (c.-780C>G; c.-135C>T; c.175C>T; c.707G>A or p.Arg236His; and c.892G>A or p.Asp298Asn; c.?430A>T) genotyped from (1) two groups of Italian Large White pigs (280+280 animals) with extreme estimated breeding values (EBVs) for back fat thickness (BFT), selected among a performance tested population of about 12,000 pigs, and from (2) 19 Italian Duroc pigs. Two haplotypes, differentiated by the c.892G>A, were identified in the Duroc populations. Four haplotypes were identified in the Italian Large White population, one of which (haplotype 4) was identified for the first time in this study. Single marker and haplotype association analyses for BFT were obtained by comparing allele and haplotype frequency differences from the two extreme tails using χ² and Cochran–Armitage trend tests. Results confirmed the effects of the c.892G>A single nucleotide polymorphism (SNP) on BFT, as also defined by different distributions in the two tails of haplotypes carrying the alternative nucleotides at this polymorphic site (P<0.01). In addition different distributions of haplotype 4 in the two extreme groups suggested that it might affect the same trait (P<0.10). Association analyses for several other traits (average daily gain, ADG; feed gain ratio, FGR; weight of lean cuts; ham weight) were carried out by using EBVs and Random Residuals: significant effects (P<0.05) were only found for the p.Asp298Asn mutation on ADG and FGR. Results did not support any relevant effect of the p.Arg236His mutation on any trait. Data reported in this study contribute to better understand the role of MC4R variants in affecting production traits in pigs, a prerequisite to consider polymorphisms in this gene for marker assisted selection.