[Association between parental MTHFR gene polymorphism 677C/T and nonsyndromic cleft lip and palate in offspring].

OBJECTIVE: To explore the association between parental genetic polymorphism of methylenetetrahydrofolate reductase (MTHFR) 677C/T and occurrence of nonsyndromic cleft lip with or without cleft palate (NSCL/P) in offspring in Shandong Province. METHODS: MTHFR genotypes were determined by polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP). Parents of 89 NSCL/P patients treated at Qilu Hospital from August, 2006 to August, 2008 and those of 64 healthy children were recruited in this case-control study. RESULTS: Frequencies of T and C alleles in mothers of patients and healthy children were 65.73% and 46.09%, and 34.27% and 53.91%, respectively (Chi-square=13.663, P<0.01). Offspring whose mothers had T alleles were 2.243 times more likely to develop NSCL/P (95%CI: 1.408-3.572). Frequencies of T and C alleles in fathers of patients and healthy children were 62.92% and 55.47%, and 37.08% and 44.53%, respectively (Chi-square=2.222, P>0.05). The chance for parents of the patient and control groups to bear an affected fetus carrying homozygous mutations were 43% and 29%, respectively (P>0.05). CONCLUSION: In Shandong Province, maternal genotype for the MTHFR 677C/T polymorphism has a significant impact on the occurrence of NSCL/P in their offspring, whilst paternal genotype for this polymorphism may not be a risk factor for NSCL/P in their offspring.

The genomics of selection in dogs and the parallel evolution between dogs and humans.

The genetic bases of demographic changes and artificial selection underlying domestication are of great interest in evolutionary biology. Here we perform whole-genome sequencing of multiple grey wolves, Chinese indigenous dogs and dogs of diverse breeds. Demographic analysis show that the split between wolves and Chinese indigenous dogs occurred 32,000 years ago and that the subsequent bottlenecks were mild. Therefore, dogs may have been under human selection over a much longer time than previously concluded, based on molecular data, perhaps by initially scavenging with humans. Population genetic analysis identifies a list of genes under positive selection during domestication, which overlaps extensively with the corresponding list of positively selected genes in humans. Parallel evolution is most apparent in genes for digestion and metabolism, neurological process and cancer. Our study, for the first time, draws together humans and dogs in their recent genomic evolution.