Alternate splicing pathways of the immunoglobulin heavy chain transcript of a teleost fish,Ictalurus punctatus

Previously we sequenced a partial cDNA clone encoding the 3' region of the message for the membrane receptor form of the heavy (mu) chain of the channel catfish which indicated that the first transmembrane (TM1) exon is spliced directly to the C mu 3 exon and not into a cryptic site within the CH4 exon, as occurs in other vertebrates. Studies utilizing polymerase chain reaction analysis of mRNA and further analysis of cDNA clones now confirm that the only detectable splicing pattern used in micron production by the channel catfish utilizes this C mu 3----TM1 pathway of pre-mRNA splicing.     

PHENOTYPIC PLASTICITY IN THE SAILFIN MOLLY,POECILIA LATIPINNA (PISCES: POECILIIDAE). II. LABORATORY EXPERIMENT

Field studies indicate that the influence of environmental factors on growth rate and size and age at maturity in sailfin mollies (Poecilia latipinna) is inconsistent over time and suggest that the marked interdemic variation in male body size in this species is the result of genetic variation. However, the role of specific environmental factors in generating phenotypic variation must be studied under controlled conditions unattainable in nature. We raised newborn sailfin mollies from four populations in laboratory aquaria under all possible combinations of two temperatures, three salinities, and two food levels to examine explicitly the influence of these environmental factors. Males were much less susceptible than females to temperature variation and were generally less plastic than females in terms of all three traits. Members of both sexes matured at larger sizes and at later ages in less saline and in cooler environments. Food levels were not sufficiently different to affect the traits we studied. The effects of temperature and salinity were not synergistic. Males from different populations exhibited different average ages and sizes at maturity, but females did not. The magnitudes of the effects we found were not substantial enough to account for the consistent interdemic differences in male and female body size that have been observed previously. Our results also indicate that no single environmental factor is solely responsible for the environmental effects observed in field experiments on growth and development. These studies, together with other work, indicate that the strongest sources of interdemic variation are genetic differences in males and differences in postmaturation growth and survivorship in females.     

Investigations of the butylcholinesterase-containing cells of the adenohypophysis of the white-crowned sparrow,Zonotrichia leucophrys gambelii

Summary In the adenohypophysis of Zonotrichia leucophrys gambelii two types of cells with butylcholinesterase(BuChE) activity can be demonstrated histochemically. Type I occurs in the cephalic lobe of the pars distalis and in the pars tuberalis; it consists of oval and round cells. It is a distinctive cell type that is identical with the amphophilic cells described by Matsuo, Vitums, King and Farner (1969). Whereas castration or inhibition of thyroid gland activity causes only minor changes in these cells, blocking of adrenal cortex activity, or adrenalectomy, causes conspicuous hyperplasia and hypertrophy suggesting that these cells are involved in the production or release of ACTH. The second type, which occurs in both cephalic and caudal lobes, consists mostly of irregularly formed cells. Various observations indicate that it is a composite group, consisting, at least in part, of degenerating cells.These investigations were supported by grants from the National Institutes of Health (S ROI NB 06812) and the National Science Foundation (GB 5969) to Professor Farner.     

Secretion of proteins and antibody fragments from transiently transfected endothelial progenitor cells

In neurodegenerative diseases such as Alzheimer's disease, Parkinson's disease, multiple sclerosis and amyotrophic lateral sclerosis, neuroinflammation can lead to blood‐brain barrier (BBB) breakdown. After intravenous or intra‐arterial injection into mice, endothelial progenitor cells (EPCs) home to the damaged BBB to promote neurovascular repair. Autologous EPCs transfected to express specific therapeutic proteins offer an innovative therapeutic option. Here, we demonstrate that EPC transfection by electroporation with plasmids encoding the reporter protein GFP or an anti‐β‐amyloid antibody fragment (Fab) leads to secretion of each protein. We also demonstrate the secreted anti‐β‐amyloid Fab protein functions in β‐amyloid aggregate solubilization.     

Key Ecological Function Peaks at the Land–Ocean Transition Zone When Vertebrate Scavengers Concentrate on Ocean Beaches

Ecosystems - Ecotones can form hot spots of biodiversity by containing species from multiple ecosystems. Because biodiversity is often linked to ecological function, we posit that rates of key...