The co-ordination between respiration and wing beats in birds

Summary Investigations in 10 species showed that respiration of birds in flight is usually co-ordinated with wing beats, but the co-ordination is not obligatory. Respiration synchronous with wing beats (11 co-ordination) was found only in pigeons and crows, the other species exhibited one of 11 other types of co-ordination. Quails, ducks and pheasants, birds with relatively high wing beat frequencies (with relatively small wings) showed a 51 co-ordination. Within species, and even during a flight the type of co-ordination changed, and simultaneously there were sudden changes in the respiration frequency. For the most part, the beginning of inspiration was linked with the (end of) upstroke and the beginning of expiration with the end of downstroke.Issued as N.R.C.C. No. 11095Dedicated to Prof. Dr. Erwin Stresemann at his 80. birthday.We are grateful to Dr. D. Jensen for enabling the work on the gulls at McMaster University in Hamilton. We also wish to thank B. A. Mackenzie and R. Charbonneau for the skillful assistance in all experiments.     

Modification of the zona-free hamster ova bioassay of boar sperm fertility and correlation with in vivo fertility

These studies were designed to evaluate the ability of the zona-free hamster ova bioassay to detect differences in fertility of boar sperm. In the first study, sperm from two previously infertile boars were compared to sperm from seven previously fertile boars. The percentage of zona-free hamster ova penetrated by sperm from the previously infertile boars was significantly lower than the percentage of ova penetrated by sperm from previously fertile boars (18% of ova penetrated vs. 83%, P < .001). In the 14 ejaculates from the previously infertile boars that had ejaculate motilities of 50% or greater, the percentage of zona-free hamster ova penetrated continued to be lower than in ejaculates from the fertile boars. One of the two previously infertile boars consistently had a normal semen analysis. The only two observed manifestations of his reduced fertility were his zero conception rate and the limited ability of his sperm to penetrate zona-free hamster ova. In the second study, females were inseminated with equal numbers of sperm from two previously fertile males and the paternity of offspring determined at birth. The experiment was replicated with four combinations of six boars. A high correlation was observed between the percentage of offspring sired and the ability to penetrate zona-free hamster ova (R = .89). Neither morphology nor the ability of the sperm to undergo an acrosome reaction during in vitro incubation was correlated with fertility in the competitive mating situation. These results suggest the zona-free hamster ova bioassay can improve the in vitro fertility assessment of fresh boar semen.     

Chromosome mapping of the human ras-related rab3A gene to 19p13.2

The rab genes belong to one of the three main branches of the ras super family. The encoded rab proteins share 38 to 75% amino acid identity with the yeast YPT1 and SEC4 proteins. We used the human rab3A cDNA to map the corresponding gene on human chromosomes by chromosome sorting and in situ hybridization. Both techniques allowed the assignment of the rab3A gene to chromosome 19 with a regional localization on 19p13.2 obtained by in situ hybridization.