Invertase activity in the midgut ofSarcophaga ruficornis andMusca domestica (diptera: Insecta)

Summary The pH for the optimum activity of the midgut invertase was 5.5 in the adults ofS. ruficornis, 6.0 in its larvae and adults ofM. domestica and 6.5 in the larvae of the latter fly. The optimum temperature was 50°C. Enzyme activity was retarded by the addition of glucose and fructose.     

A new antibacterial agent produced byStreptomyces sp. Ac6569

Zusammenfassung Ein neues, gegen Bakterien und Pilze wirsames Antibiotikum wurde aus demStreptomyces sp. Ac₆569 in der Form eines amorphen Hydrochlorids isoliert. Die Substanz ist wasserlöslich, aber fast unlöslich in organischen Lösungsmitteln, Schmp. 216–218° (Zersetzung); sie gehört zur Streptothricin-Gruppe der Antibiotika.     

Chloral hydrate induced haploidization inAspergillus nidulans

Summary This is the first report of induction of haploidization inAspergillus nidulans by chloral hydrate, which is an efficient polyploidizing agent for higher plants and a psychotropic drug for man. A new procedure has been described to isolate haploids from diploids with a very high frequency, as compared top-fluorophenylalanine, which is generally used for this purpose.     

Dissecting the architecture of a quantitative trait locus in yeast

Most phenotypic diversity in natural populations is characterized by differences in degree rather than in kind. Identification of the actual genes underlying these quantitative traits has proved difficult. As a result, little is known about their genetic architecture. The failures are thought to be due to the different contributions of many underlying genes to the phenotype and the ability of different combinations of genes and environmental factors to produce similar phenotypes. This study combined genome-wide mapping and a new genetic technique named reciprocal-hemizygosity analysis to achieve the complete dissection of a quantitative trait locus (QTL) in Saccharomyces cerevisiae. A QTL architecture was uncovered that was more complex than expected. Functional linkages both in cis and in trans were found between three tightly linked quantitative trait genes that are neither necessary nor sufficient in isolation. This arrangement of alleles explains heterosis (hybrid vigour), the increased fitness of the heterozygote compared with homozygotes. It also demonstrates a deficiency in current approaches to QTL dissection with implications extending to traits in other organisms, including human genetic diseases.     

Certain biochemical changes in the ovary of a migratory bird,Calandrella acutirostris tibetana

Summary The changes in the ovarian cholesterol, glycogen and ascorbic acid of Bagheri,Calandrella acutirostris tibetana, during its non-breeding and breeding periods were studied. There was a significant increase in all the 3 biochemical constituents during the breeding period.     

Embryonic origins of human vascular smooth muscle cells: implications for in vitro modeling and clinical application

Vascular smooth muscle cells (SMCs) arise from multiple origins during development, raising the possibility that differences in embryological origins between SMCs could contribute to site-specific localization of vascular diseases. In this review, we first examine the developmental pathways and embryological origins of vascular SMCs and then discuss in vitro strategies for deriving SMCs from human embryonic stem cells (ESCs) and induced pluripotent stem cells (iPSCs). We then review in detail the potential for vascular disease modeling using iPSC-derived SMCs and consider the pathological implications of heterogeneous embryonic origins. Finally, we touch upon the role of human ESC-derived SMCs in therapeutic revascularization and the challenges remaining before regenerative medicine using ESC- or iPSC-derived cells comes of age.     

The lateral neurosecretory cells and mating instinct in maleDysdercus koenigii (Hemiptera: Pyrrhocoridae)

Summary 5 pairs of median and 1 pair of lateral neurosecretory cell groups occur in the protocerebrum of maleDysdercus koenigii, a hemipteran pest on Hibiscus esculentus. The lateral neurosecretory cells (LNSC) are in a state of peak activity when the male engages itself in copulation. 24 h later, the LNSC are found to be inactive, but they again resume their activity 96 h after commencement of copulation. Such males soon start mating if they find another receptive female. It is believed that the secretion of LNSC in maleDysdercus koenigii is responsible for the onset of the urge for mating just as in female insects.     

Endocrine control of mating instinct in Dysdercus koenigii (Hemiptera: Pyrrhocoridae).

Five pairs of median and 1 pair of lateral neurosecretory cell groups occur in the protocerebrum of Dysdercus koenigii, a hemipteran pest on the ladies finger plant (Hibiscus esculentus). The lateral neurosecretory cells (LNSC) become active prior to, and at the time of commencement of mating and release their secretion within 24 h of commencement. The female never mates again after laying eggs and the LNSC also never become active. It is believed that LNSC secretion induces the urge for mating in the freshly emerged female and the lateral groups of NSC form the receptivity centre in the brain.