Wood duck hatch date: relationship to pairing chronology, plasma luteinizing hormone, and steroid hormones during autumn and winter

We examined variation in courtship activity and hormone levels of male and female wood ducks (Aix sponsa) in relation to hatch date. Young wood ducks were assigned in groups of 8 (4 males and 4 females) to 4 experimental pens; 2 pens contained early-hatched ducks (3-12 April) and 2 pens contained late-hatched ducks (7-16 June). Courtship behaviors occurred less frequently in October and November than in December and January-February for both early- and late-hatched groups. Early-hatched wood ducks participated in courtship more frequently and formed pair bonds sooner than late-hatched individuals. Testosterone (T) and androstenedione (AD) levels of males did not differ between treatment groups; however, average levels of luteinizing hormone (LH) were greater for early-hatched males. Differences in LH occurred in 2 of 12 samples (6 October and 3 November); otherwise, LH did not vary by treatment. Levels of T and LH in males varied temporally, but there was no significant temporal variation in AE levels. Temporal variation in hormone levels was similar for early- and late-hatched males. Estradiol (E), progesterone (P), and LH levels of females did not differ between treatment groups. There was temporal variation in levels of E and LH, but not of P; this variation was similar for early- and late-hatched females. These data indicate that behavioral differences occurring temporally and between early- and late-hatched wood ducks were not related to corresponding differences in hormone levels.     

Effects of a variety of cytokines and inducing agents on vascular permeability factor mRNA levels in U937 cells.

Vascular permeability factor (VPF) is an approximately 40-kDa disulfide-linked dimeric glycoprotein that is active in increasing blood vessel permeability, endothelial cell growth and angiogenesis. Little is known about VPF gene regulation. In this study, we investigated the effects of a variety of cytokines and inducing agents on VPF mRNA levels in the monocyte-like U937 cell line. Transforming growth factor-beta 1 caused a 1.8-fold increase in VPF mRNA levels after 4 hours, followed by a decline to basal levels by 18 hours. Phorbol 12-myristate 13-acetate, a potent inducer of the differentiation of U937 cells, caused a 12.5-fold increase in VPF mRNA levels at 24 hours, coinciding with the differentiation of these monocyte-like cells into macrophage-like cells.     

Physical mapping of the human carbonic anhydrase gene cluster on chromosome 8

A cluster of genes encoding the three cytoplasmic carbonic anhydrase isozymes CAI, CAII, and CAIII lie on the long arm of chromosome 8 (8q22) in humans. These genes have been mapped using pulsed-field gel electrophoresis. The genes lie in the order CA2, CA3, CA1. CA2 and CA3 are separated by 20 kb and are transcribed in the same direction, away from CA1. CA1 is separated from CA3 by over 80 kb and is transcribed in the direction opposite to CA2 and CA3. The arrangement of the genes is consistent with proposals that the duplication event which gave rise to CA1 predated the duplication which gave rise to CA2 and CA3. The order of these three genes differs from that suggested for the mouse based on recombination frequency.     

Polarity in higher plant dictyosomes

Summary Dictyosomes in three higher plant cell secretory systems,Zea root cap cells,Tradescantia pollen tubes and digestive glands ofDionaea fly traps, are shown to possess a structural polarity in terms of either the production of secretory vesicles, or the reaction of individual cisternae to the osmium-zinc-iodide impregnation procedure. These observations contradict previous claims that higher plant dictyosomes lack structural polarity. Doubts about the applicability of the endomembrane flow concept to higher plant cell dictyosomes are discussed in relation to the relative balance between carbohydrate and protein in secreted products. The lack of dictyosome-associated endoplasmic reticulum in some of these plant cell systems is confirmed.     

Proceranone,a new tetranortriterpenoid from Carapa procera

A new tetranortriterpenoid, named proceranone, has been isolated from the seeds of Carapa procera and its structure elucidated by IR, NMR and mass spectral studies.