Nature and the time course of the effect of CO2 on electroretinogram (ERG) in an arachnid

Summary Electroretinogram recorded from the median eye of the scorpion, Heterometrus fulvipes before and after exposure to CO₂ indicated that the rate of recovery of b wave to pre-CO₂ level was slow and delayed as compared to a wave. b wave may therefore have a more central origin than that of a wave, which finds corroboration in the results of the depth recording in this eye with the microelectrode.The equipment was a gift from USAFOSR to Prof. T. H. Bullock and Prof. K. P. Rao, and the work was carried out at the Department of Zoology, Bangalore University. I thank Dr R. V. Krishnamoorthy and Dr A. R. Kasturi Bai.     

On partial and differential bleaching experiments with the visual pigments in a fresh water euryhaline teleost (Etroplus suratensis)

Summary Visual pigment was extracted from a fresh water toleost,Etroplus suratensis and the optical density measured over a range of 300–650 nm. The absorption spectrum indicates the _max at 550 nm and a small hump at 530 nm. Through partial bleaching at 630 nm, it was confirmed that the fish possesses a mixture of 2 visual pigments: the one with the _max at 550 nm predominating over the other.     

No evidence of clonal somatic genetic alterations in cancer-associated fibroblasts from human breast and ovarian carcinomas

There is increasing evidence showing that the stromal cells surrounding cancer epithelial cells, rather than being passive bystanders, might have a role in modifying tumor outgrowth. The molecular basis of this aspect of carcinoma etiology is controversial. Some studies have reported a high frequency of genetic aberrations in carcinoma-associated fibroblasts (CAFs), whereas other studies have reported very low or zero mutation rates. Resolution of this contentious area is of critical importance in terms of understanding both the basic biology of cancer as well as the potential clinical implications of CAF somatic alterations. We undertook genome-wide copy number and loss of heterozygosity (LOH) analysis of CAFs derived from breast and ovarian carcinomas using a 500K SNP array platform. Our data show conclusively that LOH and copy number alterations are extremely rare in CAFs and cannot be the basis of the carcinoma-promoting phenotypes of breast and ovarian CAFs.     

Biochemical genetical studies on host-parasite relationship. Pathogenicity of two mutants ofFusarium vasinfectum Atk. on cotton plants

Zusammenfassung VonFusarium vasinfectum Atk. wurden nach Behandlung mit salpetriger Säure zwei auxotrophe Mutanten isoliert. Die eine ist Niacin-heterotroph und erweist sich als doppelt virulent, verglichen mit der Wildform. Die andere Mutante benötigtP-Aminobenzoesäure und ist nicht pathogen. Die Pathogenität der Mutanten scheint mit der Produktion von Fusarsäure parallel zu laufen.

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No. III. Scheme sponsored and financed by the United States Department of Agriculture under USPL 480 funds.     

The role of deubiquitinating enzymes in apoptosis

It has become apparent that ubiquitination plays a critical role in cell survival and cell death. In addition, deubiquitinating enzymes (DUBs) have been determined to be highly important regulators of these processes. Cells can be subjected to various stresses and respond in a variety of different ways ranging from activation of survival pathways to the promotion of cell death, which eventually eliminates damaged cells. The regulatory mechanisms of apoptosis depend on the balanced action between ubiquitination and deubiquitination systems. There is a growing recognition that DUBs play essential roles in regulating several binding partners to modulate the process of apoptosis. Thus, the interplay between the timing of DUB activity and the specificity of ubiquitin attachment and removal from its substrates during apoptosis is important to ensure cellular homeostasis. This review discusses the role of a few ubiquitin-specific DUBs that are involved in either promoting or suppressing the process of apoptosis.