Immunocontraception in Wild Horses: One Inoculation Provides Two Years of Infertility

ABSTRACT ABSTRACT Previous studies reported one year of contraception associated with a 1-injection porcine zona pellucida (PZP) vaccine. We have subsequently determined contraceptive effectiveness of a presumptive 1-injection, 2-year-duration PZP vaccine in free-roaming wild horses (Equus caballus) in Nevada, USA. In January 2000, we captured, freeze-branded, treated, and subsequently released 96 adult females that received 1) a primary dose of vaccine emulsion consisting of aqueous PZP and Freund's Complete Adjuvant, and 2) booster doses of PZP and adjuvant in controlled-release polymer pellets. We determined PZP release characteristics of pellets in vitro, prior to field use. We determined reproductive success in treated and untreated females through October 2004 via measurement of estrone sulfate and progesterone metabolites in fresh feces collected from the ground and by twice-annual foal counts. Among treated females, annual reproductive success from 2001 though 2004 sequentially was 5.9%, 14.0%, 32.0%, and 47.5%. Untreated females showed average reproductive success of 53.8 ± 1.3% across this period. This study revealed that: 1) PZP acted as an effective contraceptive for 2 years posttreatment; 2) some residual contraceptive effect remained in year 3; and 3) fertility returned to control levels by year 4 posttreatment. It appears that controlled-release technology can replace both the second(1-month) and annual booster injection of PZP vaccine, thereby decreasing cost and increasing efficiency of use of this vaccine in wild horse management.     

Alleviation of Seed Dormancy in the Desert ForbZygophyllum simplexL. from Pakistan

Zygophyllum simplexL. is a succulent annual that grows on thecoastal and inland saline flats around Karachi, Pakistan. Theseeds are moderately salt tolerant during germination. GerminationofZygophyllum simplexseeds under various salinity, proline,betaine, GA and kinetin treatments was determined. Proline (0.1and 1 mM) and betaine (0.1 and 1 mM) alleviated the innate dormancyof seeds, and germination reached 60–70% compared to 12%in the control set. At low salinity compatible osmotica alleviatedsome effects of salinity, but at higher NaCl concentrationsboth proline and betaine were ineffective. Gibberellic acid(0.3 and 3 mM) and kinetin (0.05 and 0.5 mM) substantially alleviatedboth innate as well as salinity-induced seed dormancy. At highersalinity (125 mM), low concentrations of kinetin (0.05 mM) andhigh concentrations of GA (3 mM) were more effective. GA completelyalleviated the effect of salinity at all concentrations used. Betaine; desert; dormancy; forb; GA; germination; halophyte; kinetin; proline; seeds; Zygophyllum simplex     

Carbon Fixation by Paphiopedilum insigne and Paphiopedilum parishii (Orchidaceae),{dagger}

Measurements of stomalal conductance, ¹⁴CO₂ fixation and aciditylevels indicate that Paphiopedilum insigne (Walhch) and P parishii(Rchb f) Stein, Orchidaceae, do not fix carbon via the Crassulaceanacid metabolism pathway Acidity, C₂ pathway, CAM, stomatal conductance     

Longevity, fecundity, change in degree of gravidity and lipid content with adult age, and lipid utilisation during tethered flight of alates of the corn leaf aphid, Rhopalosiphum maidis

The longevity, daily fecundity, degree of gravidity and lipid content of alates of varied ages, and lipid utilisation during sustained tethered flight of the corn leaf aphid, Rhopalosiphum maidis, were studied. Alates had a mean longevity of 9.7 days and a mean fecundity of 14.9 nymphs. A significant increase in the lipid content of alates before emerging as adults was observed. Newly emerged and half-day-old alates had more lipid reserve and embryos than 1-, 2-, 4-, 8-, and 16-day-old specimens. The lipid content of alates decreased significantly with age. The alates' degree of gravidity and lipid content had a low but significant correlation. Half- to 1-day-old alates flew readily and could fly for much longer durations than 2- and 4-day-old. Eight-day-old alates were not capable of flight. R. maidis utilised lipid during prolonged tethered flight. Our data suggest that there is a threshold point when alates cease utilising stored lipid as the energy source and start utilising non-lipid sources as flight fuel energy.