Biomaterial Database

Effect of changing from a short-day to long-day photoperiod on the breeding season of the brushtail possum (Trichosurus vulpecula). 1995

R T Gemmell, and C Sernia

Department of Anatomical Sciences, Physiology, and Pharmacology, University of Queensland, Brisbane, Australia.

In Queensland, possums (Trichosurus vulpecula) in the wild and in captivity first give birth during March and April and continue to give birth throughout the year until November. The possum has a gestation length of 17.5 days, gives birth to one young, and lactation continues for approximately 180 days. If the newborn possum is removed during the breeding season, the possum will ovulate approximately 9 days later and give birth approximately 26 days after removal of the pouch young (RPY). Repeated RPY may be used to determine the duration of the breeding season. In this study, the effect on the breeding season of a marked change in photoperiod From a short-day to a long-day was examined by comparing three groups of possums in different photoperiods for 13 months. One group of five female and two mail possums (group A) was housed in a natural photoperiod and a second group (B) was housed in a short-day photoperiod (10 h light: 14 h dark) throughout the study. The third group (C) was housed in a short-day photoperiod until each possum gave birth, the pouch young was removed, and the possum transferred to a long-day photoperiod room (14 h light: 10 h dark) for the remainder of the study. The possums held in a natural photoperiod, group A, gave birth to a total of 27 births in the one breeding season from March to October.(ABSTRACT TRUNCATED AT 250 WORDS)

UI	MeSH Term	Description	Entries
D009893	Opossums	New World marsupials of the family Didelphidae. Opossums are omnivorous, largely nocturnal and arboreal MAMMALS, grow to about three feet in length, including the scaly prehensile tail, and have an abdominal pouch in which the young are carried at birth.	Didelphidae,Opossum
D011374	Progesterone	The major progestational steroid that is secreted primarily by the CORPUS LUTEUM and the PLACENTA. Progesterone acts on the UTERUS, the MAMMARY GLANDS and the BRAIN. It is required in EMBRYO IMPLANTATION; PREGNANCY maintenance, and the development of mammary tissue for MILK production. Progesterone, converted from PREGNENOLONE, also serves as an intermediate in the biosynthesis of GONADAL STEROID HORMONES and adrenal CORTICOSTEROIDS.	Pregnenedione,Progesterone, (13 alpha,17 alpha)-(+-)-Isomer,Progesterone, (17 alpha)-Isomer,Progesterone, (9 beta,10 alpha)-Isomer
D011793	Queensland	A state in northeastern Australia. Its capital is Brisbane. Its coast was first visited by Captain Cook in 1770 and its first settlement (penal) was located on Moreton Bay in 1824. The name Cooksland was first proposed but honor to Queen Victoria prevailed. (From Webster's New Geographical Dictionary, 1988, p996 & Room, Brewer's Dictionary of Names, 1992, p441)
D012098	Reproduction	The total process by which organisms produce offspring. (Stedman, 25th ed)	Human Reproductive Index,Human Reproductive Indexes,Reproductive Period,Human Reproductive Indices,Index, Human Reproductive,Indexes, Human Reproductive,Indices, Human Reproductive,Period, Reproductive,Periods, Reproductive,Reproductive Index, Human,Reproductive Indices, Human,Reproductive Periods
D001723	Birth Rate	The number of births in a given population per year or other unit of time.	Natality,Age-Specific Birth Rate,Age-Specific Fertility Rate,Fertility Rate,Age Specific Birth Rate,Age Specific Fertility Rate,Age-Specific Birth Rates,Age-Specific Fertility Rates,Birth Rate, Age-Specific,Birth Rates,Fertility Rate, Age-Specific,Fertility Rates,Natalities,Rate, Age-Specific Fertility,Rate, Birth,Rate, Fertility
D001947	Breeding	The production of offspring by selective mating or HYBRIDIZATION, GENETIC in animals or plants.	Breedings
D005260	Female		Females
D000818	Animals	Unicellular or multicellular, heterotrophic organisms, that have sensation and the power of voluntary movement. Under the older five kingdom paradigm, Animalia was one of the kingdoms. Under the modern three domain model, Animalia represents one of the many groups in the domain EUKARYOTA.	Animal,Metazoa,Animalia
D012621	Seasons	Divisions of the year according to some regularly recurrent phenomena usually astronomical or climatic. (From McGraw-Hill Dictionary of Scientific and Technical Terms, 6th ed)	Seasonal Variation,Season,Seasonal Variations,Variation, Seasonal,Variations, Seasonal
D017440	Photoperiod	The time period of daily exposure that an organism receives from daylight or artificial light. It is believed that photoperiodic responses may affect the control of energy balance and thermoregulation.	Dark-Light Cycle,Daylight Cycle,Light Cycle,Light-Dark Cycle,Cycle, Dark-Light,Cycle, Daylight,Cycle, Light,Cycle, Light-Dark,Cycles, Dark-Light,Cycles, Daylight,Cycles, Light,Cycles, Light-Dark,Dark Light Cycle,Dark-Light Cycles,Daylight Cycles,Light Cycles,Light Dark Cycle,Light-Dark Cycles,Photoperiods