Whole-genome SNP genotyping unveils ancestral and recent introgression in wild and domestic goats.

After the domestication of goats around 10,000 years before the present (BP), humans transported goats far beyond the range of their wild ancestor, the bezoar goat. This brought domestic goats into contact with many wild goat species such as ibex and markhor, enabling introgression between domestic and wild goats. To investigate this, while shedding light on the taxonomic status of wild and domestic goats, we analysed genome-wide SNP data of 613 specimens from 14 taxonomic units, including Capra hircus, C. pyrenaica, C. ibex (from Switzerland, Austria, Germany and Slovenia), C. aegagrus aegagrus, C. a. cretica, C. h. dorcas, C. caucasica caucasica, C. c. severtzovi, C. c. cylindricornis, C. falconeri, C. sibirica sibirica, C. s. alaiana and C. nubiana, as well as Oreamnos americanus (mountain goat) as an outgroup. To trace gene flow between domestic and wild goats, we integrated genotype data of local goat breeds from the Alps as well as from countries such as Spain, Greece, Türkiye, Egypt, Sudan, Iran, Russia (Caucasus and Altai) and Pakistan. Our phylogenetic analyses displayed a clear separation between bezoar-type and ibex-type clades with wild goats from the Greek islands of Crete and Youra clustered within domestic goats, confirming their feral origin. Our analyses also revealed gene flow between the lineages of Caucasian tur and domestic goats that most likely occurred before or during early domestication. Within the clade of domestic goats, analyses inferred gene flow between African and Iberian goats. The detected events of introgression were consistent with previous reports and offered interesting insights into the historical relationships among domestic and wild goats.

Pyloric sphincter dysfunction in nNOS-/- and W/Wv mutant mice: animal models of gastroparesis and duodenogastric reflux.

BACKGROUND & AIMS: Nitrergic nerves and interstitial cells of Cajal (ICC) have been implicated in the regulation of pyloric motility. The purpose of these studies was to define their roles in pyloric function in vivo. METHODS: Pyloric sphincter manometry was performed in wild-type controls, neuronal nitric oxide synthase-deficient (nNOS(-/-)) mice, and ICC-deficient W/W(v) mice, and the effect of deafferented cervical vagal stimulation was examined. RESULTS: Mice showed a distinct approximately 0.6-mm-wide zone of high pressure at the antroduodenal junction, representing the pyloric sphincter. In wild-type controls, the pylorus exhibited tonic active pressure of 12.4 +/- 1.6 mm Hg with superimposed phasic contractions. The motility indices, minute motility index, and total myogenic activity were reduced by vagal stimulation, and the reduction was antagonized by the nitric oxide synthase inhibitor N(G)-nitro-L-arginine methyl ester (L-NAME). In nNOS(-/-) mice, pyloric basal tone, minute motility index, and total myogenic activity were not significantly different from those in controls, but vagal stimulation paradoxically increased pyloric motility. In contrast, the W/W(v) mice had significantly reduced resting pyloric pressure that was suppressed by vagal stimulation in an L-NAME-sensitive manner. The stomachs of fasted nNOS(-/-) mice showed solid food residue and bezoar formation, while W/W(v) mice showed bile reflux. CONCLUSIONS: In nNOS(-/-) mice, loss of nitrergic pyloric inhibition leads to gastric stasis and bezoars. In contrast, basal pyloric hypotension with normal nitrergic inhibition predisposes W/W(v) mice to duodenogastric bile reflux.