No abstract

The chromosome banding patterns of eight species of birds of the order Galliformes have been compared to determine their degree of chromosomal homology. The species studied were domestic chicken (Gallus gallus), Japanese quail (Coturnix coturnix), guineafowl (Numida meleagris), peafowl (Pavo cristatus), Ring-necked pheasant (Phasianus colchicus), turkey (Meleagris gallopavo), Sagegrouse (Centrocercus urophasianus), and Bob-white quail (Colinus virginianus). These species were selected as key genera in a preliminary study of evolutionary relationships in the order Galliformes.The chromosome banding patterns defined two major groups, with Gallus most nearly approaching the ancestral karyotype. Gallus, Numida, Coturnix, and Pavo retain the ancestral submetacentric chromosome 2, which also occurs in the cracid, Crax mitu (DeBoer and Belterman, 1981), and certain other bird orders. Coturnix differs from Gallus by four inversions. Numida differs from Gallus by a centric fusion of two microchromosomes which formed a unique new macrochromosome. Pavo differs from Gallus by two centric fusions which result in two unique macrochromosomes. The second major group, Phasianus, Meleagris, Colinus, and Centrocercus all lack the submetacentric 2 and have two separate chromosomes in its place as a result of a centric fission event. All of these species also possess the unmodified 4 seen in C. mitu, in place of the modified 4 seen in the Gallus group. Meleagris is similar to Phasianus; it differs mainly by an inversion on the Z chromosome. Colinus differs from Phasianus by an inversion on 1. Centrocercus differs from Phasianus by a centric fusion which produced a unique chromosome. Gallus, Pavo, Numida, and Coturnix are related but distinct lines which are clearly separate from Phasianus. Meleagris, Colinus, and Centrocercus represent closely related lines that developed in the new world from an early North American phasianid. Chromosome banding patterns indicate that the ancestral stock was karyotypically similar to Phasianus. Comparison of the data from this study and that of DeBoer and Belterman (1981) for C. mitu indicates a close relationship of the cracids to other galliform birds, in contrast to the opinion of Prager and Wilson (1979) based on studies of lysozymes and other proteins. The chromosome data supports the conclusions from several other lines of investigation that challenge the taxonomic treatment of the Galliformes which regards the turkey, guinea fowl, and grouse as belonging to separate families, yet unites divergent lines such as Old World quail, New World quail, peafowl, and true pheasants into a single family, Phasianidae. Treatment of each of the major lines indicated in this study at the subfamily level seems more consistent with the available data.

No abstract

The golden Syrian hamster is the model of choice or the only rodent model for studying many human diseases. However, the lack of gene targeting tools in hamsters severely limits their use in biomedical research. Here, we report the first successful application of the CRISPR/Cas9 system to efficiently conduct gene targeting in hamsters. We designed five synthetic single-guide RNAs (sgRNAs)—three for targeting the coding sequences for different functional domains of the hamster STAT2 protein, one for KCNQ1, and one for PPP1R12C—and demonstrated that the CRISPR/Cas9 system is highly efficient in introducing site-specific mutations in hamster somatic cells. We then developed unique pronuclear (PN) and cytoplasmic injection protocols in hamsters and produced STAT2 knockout (KO) hamsters by injecting the sgRNA/Cas9, either in the form of plasmid or mRNA, targeting exon 4 of hamster STAT2. Among the produced hamsters, 14.3% and 88.9% harbored germline-transmitted STAT2 mutations from plasmid and mRNA injection, respectively. Notably, 10.4% of the animals produced from mRNA injection were biallelically targeted. This is the first success in conducting site-specific gene targeting in hamsters and can serve as the foundation for developing other genetically engineered hamster models for human disease.

Fetal movement, observed by ultrasound imaging, was significantly reduced (P less than or equal to 0.001) in pregnant goats gavaged with Conium seed and Nicotiana glauca and temporarily reduced with fresh Conium plant. Conium seed and Nicotiana glauca induced cleft palate and multiple congenital contractures in 100% of the kids born to pregnant goats gavaged with these plants. Multiple congenital contractures included torticollis, scoliosis, lordosis, arthrogryposis, rib cage anomalies, over extension, and flexure and rigidity of the joints. However, in goats gavaged with fresh Conium plant, fetal movement was inhibited for only about 5 hours after each individual dosage and gradually returned to control levels 12 hours after dosing. Fetal malformations in this group were limited from modest to moderate contractures of the front limbs, which resolved by 8-10 weeks post partum. No cleft palates were induced. Fetal movement was not inhibited in goats fed Lupinus caudatus and no cleft palates or multiple congenital contractures were induced in their offspring. The duration of the reduction in fetal movement appears to be an important factor in the severity and permanence of the deformities, particularly with cleft palate, spinal column defects, and severe joint deviation and fixation.