effect of perfusion with low temperature locke solution on the isolated hearts of adult rabbits and mongrel puppies was studied. the study showed no arrhythmias or myocardial fibrillation at low temperatures in the isolated mammalian heart.

background: rna interference (rnai) is a phenomenon uses double-stranded rna (dsrna) to specifically inhibit gene expression. the non-specific silencing caused by interferon response to dsrna in mammalian cells limits the potential of utilizing rnai to study gene function. duplexes of 21-nucleotide short interfering dsrna (sirna) inhibit gene expression by rnai. in some organisms, sirna can als...

By varying all combinations of developmental stages and pulse exposures of zebrafish embryos, effect of salinity (S) was examined. Zebrafish embryos survived until hatching at 2‰ S alone. Tolerance to salinity increased with advancing developmental stage, i.e. the gastrulae were more tolerant to salinity change than the blastulae and the blastulae were more tolerant than the cleaving embryos. C...

The formation of testes or ovaries in the mammalian embryo is critical in determining sexual identity and the ability to reproduce. Recent studies have begun to illuminate the cellular signalling events required for development of functional testes.

Preparation of polytene chromosomes in Culex species is very difficult and the available techniques are not always reproducible. Presuming these problems might be due to lack of an appropriate technique to deal with these long and fragile chromosomes invested with ectopic pairings and sticky ends, certain promising methods with several modifications have been tried. During the process, recently...

Early mammalian embryos exhibit remarkable plasticity, as highlighted by the ability of separated early blastomeres to produce a whole organism. Recent work in the mouse implicates a network of transcription factors in governing the establishment of the primary embryonic lineages. A combination of genetics and embryology has uncovered the organisation and function of the components of this netw...

Combinations of tissues from Xenopus blastulae have been used to identify several mechanisms that limit the number of animal cells forming muscle after induction by vegetal cells. The results disagree with a model in which direct physical contact or very close proximity between animal and vegetal cells restricts the number of cells that receive the inductive signal. Rather it seems that a diffu...

The endoplasmic reticulum (ER) consists of a polygonal network of sheets and tubules interconnected by three-way junctions. This network undergoes continual remodeling through competing processes: the branching and fusion of tubules forms new three-way junctions and new polygons, and junction sliding and ring closure leads to polygon loss. However, little is known about the machinery required t...