Morphological Differences In Tardigrade Spermatozoa Induce Variation In Gamete Motility

BackgroundFertilization is an event at the beginning of ontogeny. Successful fertilization depends on strategies for uniting female and male gametes that developed throughout evolutionary history. In tardigrades, investigations of reproduction have revealed that released spermatozoa swim in the water to reach a female, after which the gametes are stored in her body. The morphology of the spermatozoa includes a coiled nucleus and a species-specific-length acrosome. Although the mating behaviour and morphology of tardigrades have been reported, the motility of male gametes remains unknown. Here, using a high-speed camera, we recorded the spermatozoon motilities of two tardigrades, Paramacrobiotus sp. and Macrobiotus shonaicus, which have longer and shorter spermatozoa, respectively.ResultsThe movement of spermatozoa was faster in Paramacrobiotus sp. than in M. shonaicus, but the beat frequencies of the tails were equal, suggesting that the long tail improved acceleration. In both species, the head part consisting of a coiled nucleus and an acrosome did not swing, in contrast to the tail. The head part of Paramacrobiotus sp. spermatozoa swung harder during turning; in contrast, the tail of M. shonaicus moved more widely than the head. Finally, after mating, the spermatozoa that reached the female aggregated around the cloaca while waiting to enter her body in both tested species.ConclusionsThis study provides results for the first observations and analyses of individual spermatozoon motility in tardigrades. A comparison of the spermatozoon movements of the two tardigrades suggested that the motilities of the male gametes were affected by morphological differences, where the longer spermatozoa swam faster and the shorter ones showed more stable swimming. Swimming was mainly induced by tail movement, but the long head of Paramacrobiotus sp. spermatozoa might be especially important for turning. In addition, observations of mated female cloacae suggested that the head parts of the spermatozoa were required for aggregation around the cloaca of a mated female.

Polyandry in the Fruit Fly Bactrocera dorsalis Hendel (Diptera: Tephritidae)

The Oriental fruit fly, Bactrocera dorsalis (Hendel) is a global pest of a wide variety fruits. Due to its importance, the sterile insect technique (SIT) has raised attention as a safe and sustainable solution to this pest. Successful SIT programs require a comprehensive understanding on the mating behavior of this species. Females of oriental fruit flies are known monandrous which implies that females only mate once with one male. This experiment aimed to confirm that female flies were able to mate more than once with the same (multiple mating) or different males (polyandry) in certain period of time. Four different experiments were conducted to test the hypothesis: receptivity a female to the same male (1) and different males (2) in a cage for 11 days; receptivity a mated female with the same male (3) and different males (4) in a cage for 14 days after the first mating. Results indicated that a part of the female oriental fruit flies was capable to mating more than once with the same or different males.

Pregnancy and Lactation Alter Vitamin A Metabolism and Kinetics in Rats under Vitamin A-Adequate Dietary Conditions

Objectives We investigated the impact of pregnancy and lactation on vitamin A (VA) metabolism and kinetics in rats, hypothesizing that this changed physiological status would perturb whole-body VA kinetics. Such information may be informative for future dietary recommendations. Methods Ten female rats (7 wk of age) and 6 male rats (9 wk of age) were fed an AIN-93 G diet upon arrival. After 1 week of acclimation, female rats received an oral dose of 3H-labeled retinol as the tracer to initiate the kinetic study. On d 21 after dosing (when 3H-retinol was expected to reach a log-linear terminal slope), 6 female rats were mated and checked daily for a vaginal plug to determine the date of pregnancy. On the day of delivery, litter size was adjusted to 10 pups/dam. Serial blood samples were collected from each female rat at 27–28 time points after dose administration until dams and pups were euthanized on d 14 of lactation. Hematocrit was measured, plasma tracer level was determined, and plasma fraction of dose vs. time was plotted. Model-based compartmental analysis will be applied to the plasma tracer data to develop VA kinetic models. Results All mated female rats became pregnant (pregnant group, PG, n = 6). Non-mated female rats were studied as non-pregnant controls (CN, n = 4). No difference was observed in hematocrit between PG and CN rats, suggesting no significant change in plasma volume expansion. Before breeding, plasma tracer response profiles were similar to CN rats. However, a consistent decline in plasma tracer levels was observed in PG rats during the middle of pregnancy, followed by a rise in late pregnancy, whereas such a change did not occur in CN rats. Moreover, during lactation, PG rats exhibited a steeper terminal slope compared to CN rats, indicating a more rapid utilization of VA in these lactating rats. Conclusions Pregnancy and lactation resulted in altered VA metabolism and kinetics in rats. Further analysis using mathematical modeling will explore the changes in kinetic parameters that underlie the perturbations we have observed in VA kinetics. Funding Sources National Institutes of Health.

Biology of Raoiella indica Hirst. (Acari: Tenupalpidae) on Arecanut Leaves under Laboratory Conditions

Biology of Raoiella indica Hirst was studied under laboratory at 27 ± 2°C temperature and 79 ± 5.75 percent RH. The finding showed that life cycle of R. indica consisted of five stages viz., eggs, larva, protonymph, deutonymph and adult. The eggs incubation period of R. indica was 9.790 ± 1.94 days. The larval body measured 0.09 and 0.13 mm in length and 0.08 to 0.10 mm in width and lived for 8.35 ± 0.84 days. The total developmental period of female was 29.80 ± 2.73 days and male took 31.27±40 days. Mated female lived for longer time and laid higher number of eggs than unmated female.

24 Field experience and challenges facing sow production today, industry strategies

I started in the swine industry in 1973 and served for the last 16 years as one of the owners of Swine Management Services (SMS), LLC. I have spent time in a lot of swine facilities of all sizes and ages, and I have seen lots of ideas tried and changes made both positive and negative. I feel that good sow data is your road map to monitoring farms and changes as they are made. SMS has created a company that takes sow reports, does the analysis, and sends written reports to the farm and management for review. SMS currently works with over 450,000 sows in the industry. The farm benchmarking program has 1.6+ million sows from 900+ farms in the United States, Canada, and Australia with data goes back 13 years. It compares farms based on pigs weaned / mated female / year with range of <18 to 34+ pigs. Top farms have figured out the need for quality labor, and they know that gilts are the key to the future—and they will make farrowing changes to improve day 1 care procedures to save more of those pigs. We now see farms with total born at 16+ pigs, pigs weaned per litter at 13+ pigs, pigs weighing 13+ pounds at 19 day weaning age, and sows after weaning coming back into heat in less than 5 days with 95+% breed by day 7. What are their bodies going through? I feel that the ability to manage and feed these high-producing females needs researching. Will that include a lot of work on the nutrition side, floors for sows in lose sows housing, and free stalls in lactation? Where is the trained labor needed coming from?