Location of an eye mutant in the onion flyHylemya antiqua meigen using a pericentric chromosome inversion

Summary With the use of a pericentric inversion in chromosome 3, an eye color mutant in the onion fly was located in chromosome 3. No recombination occurs in males; 40.2% recombination was observed in females. This linkage through the male facilitates further cytogenetic research on structural aberrations involving chromosome 3.     

Assortative mating between chromosome forms of the mole rat, Spalax ehrenbergi.

Females of two parapatric chromosomal forms (2n = 52 and 2n =58) of the fossorial mole rat, Spalax ehrenbergi, in Israel, were tested for mate selection between two alternative, a homo- and a heterochromosomal, males. Estrous females significantly preferred the male of their own chromosomal form, on the basis of several behavioural criteria. The evolutionary significance of the positive assortative mating found, lies presumably in reinforcing reproductive isolation between the chromosome forms, thereby contributing to finalize speciation.     

Disaccharidase rhythm in rat small intestine; no relationship with mitosis rhythm.

Same circadian difference in the specific activities of sucrase and maltase was observed in the purified brush border fraction as in the crude homogenate of the mucosa of rat small intestine, suggesting that the disaccharidase rhythm is not due to the mitosis rhythm of epithelial cells.     

Assortative mating between chromosome forms of the mole rat,Spalax ehrenbergi

Females of two parapatric chromosomal forms (2n=52 and 2n=58) of the fossorial mole rat,Spalax ehrenbergi, in Israel, were tested for mate selection between two alternative, a homo- and a heterochromosomal, males. Estrous females significantly preferred the male of their own chromosomal form, on the basis of several behavioural criteria. The evolutionary significance of the positive assortative mating found, lies presumably in reinforcing reproductive isolation between the chromosome forms, thereby contributing to finalize speciation.     

Demonstration of a tryptaminergic mechanism in the rat beta-cell.

Yellow 5-HT fluorescence has been histochemically demonstrated in rat pancreatic islet cells in animals injected with L-5-HTP with or without pretreatment with the monoaminoxidase inhibitor nialamide. This fluorescence was not observed after inhibition of the aromatic amino acid decarobxylase. The results strongly suggest the presence of a tryptaminergic mechanism in the rat islet cells.     

The karyotype of the black rat (Rattus rattus L.). Another population with a 38-chromosomes complement

Riassunto In una popolazione italiana diRattus rattus L. è stato messo in evidenza un cariotipo a 38 cromosomi; la differenza nel numero diploide rispetto a quanto noto per altre popolazioni della stessa specie è dovuta a due fusioni centriche in condizione omozigote. Il confronto con i cariotipi forniti da altri autori per la specieRattus rattus ci fa proporre anche per questa specie di Roditori la presenza di un fenomeno di polimorfismo cromosomico.     

Evidence for no relationship of the pineal activity with the neonatal shrinkage of Leydig cells in the rat

Summary The collective volume of Leydig cells in prenatally pinealectomized newborn rats declined as sharply as in intact newborn rats. Also, the collective volume in pups born in the dark declined in a fashion similar to that in pups born in the light. The results indicate that neither the pineal gland nor the light is responsible for the neonatal shrinkage of Leydig cells.This study was supported in part by a Grant-in Aid for Scientific Research (No. 548067) from the Ministry of Education, Science and Culture of Japan.     

Autoradiographic localization of the uptake of 3H-beta-alanine in rat nervous tissue cultures.

Autoradiographic studies on the uptake of 3H-beta-alanine have shown that, in spinal cord and brain stem cultures, both neurones and glial cells have accumulated the amino acid. In contrast, in cultures of cerebellum and dorsal root ganglia, 3H-beta-alanine was only t aken up by glial elements.     

Disaccharidase rhythm in rat small intestine; no relationship with mitosis rhythm

Summary Same circadian difference in the specific activities of sucrase and maltase was observed in the purified brush border fraction as in the crude homogenate of the mucosa of rat small intestine, suggesting that the disaccharidase rhythm is not due to the mitosis rhythm of epithelial cells.     

On the relative position of the centromere of chromosome 3 inDrosophila melanogaster

Zusammenfassung HomozygoteDrosophila-melanogaster-Weibchen, genetisch markiert mit scarlet (st), Kinked (Ki) und pink peach (P^p) wurden bestrahlt, um Compound-3-Chromosomen herzustellen. Es wurden ausschliesslich st/st- und P^p Ki/Ki(?) P^p-Compoundchromosomen gefunden. Dies zeigt, dass das Zentromer links der Markierung Kinked liegt.

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This work was supported by Schweizerischer Nationalfonds zur Förderung der wissenschaftlichen Forschung.     

Autoradiographic localization of testosterone-3H in the female rat brain and estradiol-3H in the male rat brain

Zusammenfassung Eine halbe Stunde nach der i.v. Injektion wurde Testosterone-³H von den Nerven- und Glialzellen innerhalb des Gehirns der weiblichen Ratte und Estradiol-³H innerhalb des Gehirns der männlichen Ratte aufgenommen. Zwei Stunden nach der Injektion war die Aufnahme in hohem Masse nur noch in gewissen Teilen des hypothalamisch-limbischen Systems vorhanden.

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This investigation was supported by grants from NASA (No. NsG 496) and the John A. Hartford Foundation to Dr.H.-L. Teuber, and from the U.S. Atomic Energy Commission to Dr.J. Altman, both of the Massachusetts Institute of Technology, and the work was performed while the author was at M.I.T.     

Oceanian type black rats (Rattus rattus) with a subtelocentric M2 chromosome and C-type transferrin obtained from North America

Résumé Dix rats (Rattus rattus) d'une colonie californienne ont été examinés. Cinq sont de type océanique. Les cinq autres ont 1 paire M₂ hétéromorphe, formée d'un métacentrique et d'un sub-métacentrique, ce qui implique une inversion péricentrique. Les transferrines sont du type océanique.