Polymorphisms and expression of the WNT8A gene in Hirschsprung's disease

Effects of genetic variants of the bovine WNT8A gene on nine important growth traits in beef cattle

WNT-β-catenin-TCF pathway is involved in carcinogenesis and foetal development. As a member of the WNT gene family, Wnt8A encodes secreted signalling proteins and responds to many biological processes.However, similar research on the effects of genetic variations of Wnt8A gene on growth traits is lacking. Therefore, in this study, polymorphisms of Wnt8A were detected in 396 animals from Chinese Qinchuan cattle using DNA pool sequencing and PCR-RFLP methods. Four novel single-nucleotide polymorphisms (SNPs) of Wnt8A gene were identified, including three mutations in introns (g.T-445C, g.G244C and g.G910A) and one in exon (g.T4922C). Additionally, we examined the associations of four SNPs with growth traits. The results revealed that SNP2 (g.G244C) was significantly associated with shoulder height, hip height, body length, hip width, and body weight (P < 0.05). SNP3 (g.G910A) also displayed notable effects on hip width (P < 0.05). Meanwhile, the haplotype combination CC-GC-GA-CC was strongly associated with heavier, taller and longer animals (P < 0.05). These results show that the Wnt8A gene may be a potential candidate gene, and the SNPs could be used as molecular markers in early marker-assisted selection in beef cattle breeding programmes.

Hirschsprung's disease: Historical notes and pathological diagnosis on the occasion of the 100(th) anniversary of Dr. Harald Hirschsprung's death

Hirschsprung's disease (HSCR) or congenital megacolon is one of the differential diagnoses of chronic constipation mostly in infancy and may indeed represent a challenge for pediatricians, pediatric surgeons, and pediatric pathologists. The diagnosis relies clearly on the identification of the absence of ganglion cells at the plexuses (submucosus and myentericus) of the bowel wall. HSCR is usually located at the terminal (distal) rectum with potential pre-terminal or proximal extension to the less distal large bowel (sigmoid colon). Astonishingly, there is some evidence that Hindu surgeons of prehistoric India may have been exposed and had considerable knowledge about HSCR, but this disease is notoriously and eponymously named to Dr. Harald Hirschsprung (1830-1916), who brilliantly presented two infants with fatal constipation at the Berlin conference of the German Society of Pediatrics more than one century ago. Historical milestones and diagnosis of HSCR (originally called "Die Hirschsprungsche Krankheit") are reviewed. More than 100 years following his meticulous and broad description, HSCR is still a puzzling disease for both diagnosis and treatment. HSCR remains a critical area of clinical pediatrics and pediatric surgery and an intense area of investigation for both molecular and developmental biologists.

Expression patterns of dishevelled-2 in different colon tissue segments in Hirschsprung's disease

Hirschsprung's disease (HSCR) is a congenital disorder characterized by an absence of enteric ganglion cells in the terminal regions of the gut during development. To date, the cause of HSCR remains unclear, although the pathogenesis of this complex disease is hypothesized to be influenced by numerous genetic and environmental factors. Dishevelled‑2 (DVL‑2) is a subtype of the dishevelled protein, which is known to be involved in embryonic development. In the present study, the pathogenesis of HSCR was investigated by measuring the expression of the DVL‑2 gene and protein using reverse transcription‑quantitative polymerase chain reaction (RT‑qPCR), western blotting and immunohistochemistry staining in the aganglionic and ganglionic segments of colonic tissues in patients with HSCR. The results showed that the level of DVL‑2 mRNA in the aganglionic segments was 0.28 fold that of the ganglionic segments. Similarly, the protein expression of DVL‑2 was lower (11.31±2.23) in the aganglionic segments than that of the ganglionic segments (35.21±2.66), as assessed by western blot analysis. Furthermore, immunohistochemical staining demonstrated that DVL‑2 expression was significantly higher in the mucosal and submucosal layers from ganglionic colon segments compared with that from the aganglionic segments. The data suggest that the expression of DVL‑2 in colon tissue segments may be important in the pathogenesis of HSCR.