Genetical and histological studies on a mouse displaying microphthalmia and cataract

A male mouse displaying bilateral microphthalmia and cataract was found among the offspring of pregnant Slc: ICR mouse treated intraperitoneally with 10 mg/kg methylnitrosourea on gestational day 4. This mutant has been maintained by brother-sister mating. By the mating test with normal Slc: ICR mice, this character was revealed to be inherited by an autosomal single recessive gene. Linkage test with the brown locus showed that this mutant gene is linked with the B gene and mapped on chromosome 4. The histological study of the eyes of adult mutant mice revealed various abnormalities all over the eyes, especially in the lens and neural retina. Embryologically, the mutant mice showed persistent connection between the lens vesicle and the surface ectoderm by a cellular stalk, and also the formation of retinal infolding, in the early stages of eye development. Both were considered to be responsible for the consequent abnormal development and degradation of the lens. These results suggest that the mutant mouse we found may be an allele of the dysgenetic lens (dyl) reported by Sanyal and Hawkins.     

Genetical studies in the genusSorghum

Summary The mode of inheritance of one seedling character and nine mature plant characters has been worked out in detail in the different interspecific crosses in the genusSorghum. The majority of the factor pairs exhibited simple inheritance. However, clear evidence for breakdown of dominance in different genetic backgrounds and data for the presence of modifier gene complexes has also been obtained. The implication of these results to the genetic evolution of the variousSorghums species, is critically discussed. Further, the bearing of loci found duplicate with respect to various qualitative characters, has also been considered in relation to the polyploid origin ofArundinacea Sorghums. The genetics of the two new variants have been studied and the taxonomic importance of such anomalies is brought out.

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Zusammenfassung Die Vererbungsweise von Merkmalen innerhalb der GattungSorghum wurde an verschiedenen interspezifischen Kreuzungen eingehend untersucht (1 Samenmerkmal, 9 Merkmale der reifen Pflanze). Die Mehrzahl der Faktorenpaare zeigte einfachen Erbgang. Es ergaben sich jedoch auch klare Beweise für Dominanzverschiebungen in verschiedenem genetischem Milieu und Hinweise auf das Vorliegen von Modifikationsgenen. Die Folgerungen aus diesen Ergebnissen für die genetische Evolution der verschiedenenSorghum-Arten wurden kritisch diskutiert und die Bedeutung der für verschiedene qualitative Merkmale gefundenen polymeren Gene in Beziehung zum polyploiden Ursprung derArundinacea-Sippe vonSorghum behandelt. Die Genetik zweier neuer Varianten ist untersucht und die taxonomische Bedeutung derartiger Anomalien dargelegt worden.

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These studies were largely undertaken at the Division of Botany, I.A.R.I., New Delhi where the authors were previously located. They are, therefore, grateful to the Director, I.A.R.I., Dean of P.G. School and Head of the Division of Botany for their keen interest and facilities. One of us (M.A.T.) is also grateful to the Government of Maharashtra (Department of Agriculture), Dr.M. B. Ghatge, Director of Agriculture, Maharashtra State and Dr.B. S. Kadam for encouragement during the course of this investigation.     

Genetical studies on oenothera. IV

Ohne Zusammenfassung