- 1 Introduction
- 2 Some Recent Findings
- 3 Estrous Cycle Stages
- 4 Rat Estrous Cycle
- 5 Mouse Estrous Cycle
- 6 Pig Estrous Cycle
- 7 Dog Estrous Cycle
- 8 Bovine Estrous Cycle
- 9 References
- 10 External Links
- 11 Glossary Links
The estrous cycle (British spelling, oestrous) is the main reproductive cycle of other species females of non-primate vertebrates, for example rats, mice, horses, pig have this form of reproductive cycle. Also do not confuse with "estrus", which is a phase of the cycle.
There are also a variety of different forms:
- Polyestrous Animals - Estrous cycles throughout the year (cattle, pigs, mice, rats).
- Seasonally Polyestrous Animals - Animals that have multiple estrous cycles only during certain periods of the year (horses, sheep, goats, deer, cats).
- Monestrous Animals - Animals that have one estrous cycle per year (dogs, wolves, foxes, and bear)
Some Recent Findings
|More recent papers|
References listed on the rest of the content page and the associated discussion page (listed under the publication year sub-headings) do include some editorial selection based upon both relevance and availability.
Bonnie Chaban, Matthew G Links, Teenus Paramel Jayaprakash, Emily C Wagner, Danielle K Bourque, Zoe Lohn, Arianne Yk Albert, Julie van Schalkwyk, Gregor Reid, Sean M Hemmingsen, Janet E Hill, Deborah M Money Characterization of the vaginal microbiota of healthy Canadian women through the menstrual cycle. Microbiome: 2014, 2;23 PMID:25053998 Shehla Haider, Nighat Mannan, Ayesha Khan, Masood A Qureshi Influence of anthropometric measurements on abnormal gonadotropin secretion in women with polycystic ovary syndrome. J Coll Physicians Surg Pak: 2014, 24(7);463-6 PMID:25052966 Raffaella Fabbri, Maria Macciocca, Cristina Melotti, Gianandrea Pasquinelli, Rossella Vicenti, Maria Letizia Bacchi Reggiani, Daniela Terribile, Stefano Venturoli Anti-Müllerian hormone as an ovarian reserve marker in young cancer women who undergo ovarian tissue cryopreservation. Future Oncol: 2014, 10(8);1343-51 PMID:25052745 Mingoo Kim, Heewon Seo, Yohan Choi, Jangsoo Shim, Heebal Kim, Chang-Kyu Lee, Hakhyun Ka Microarray Analysis of Gene Expression in the Uterine Endometrium during the Implantation Period in Pigs. Asian-australas. J. Anim. Sci.: 2012, 25(8);1102-16 PMID:25049669 Yohan Choi, Heewon Seo, Jangsoo Shim, Mingoo Kim, Hakhyun Ka Regulation of S100G Expression in the Uterine Endometrium during Early Pregnancy in Pigs. Asian-australas. J. Anim. Sci.: 2012, 25(1);44-51 PMID:25049477
Estrous Cycle Stages
The descriptions below refer to the "typical" mammalian cycle.
- proestrus - estrus - metestrus - diestrus
The first stage in the estrous cycle immediately before estrus characterized by development of both the endometrium and ovarian follicles.
The second stage in the estrous cycle immediately before metestrus characterized by a receptivity to a male and to mating, often referred to as "heat" or "in heat". Pheromones may also be secreted only at this stage of her cycle.
The third stage in the estrous cycle immediately before diestrus characterized by sexual inactivity and the formation of the corpus luteum.
The last stage in the estrous cycle immediately before the next cycle proestrus characterized by a functional corpus luteum and an increase in the blood concentration of prosgesterone.
Not a stage in the estrous cycle, but a prolonged period of sexual rest where the reproductive system is quiescent.
Rat Estrous Cycle
One of the best characterised reproductive cycles, though different species of rats may differ in reproduction. In general, puberty occurs at 6-8 weeks when the oestrous cycle commences each cycle is 4-5 days.
The estrous cycle is Polyoestrous with an estrous period of approximately 12 hours.
Mouse Estrous Cycle
The mouse oestrus cycle is 4-6 days, with oestrus lasting less than 1 day. The estrous cycle stops during lactation except for one oestrus 12-20 hours postpartum. The information below refers to determining the stage of the estrous cycle in the mouse by the appearance of the vagina.
- Estrous Diestrus - Vagina has a small opening and the tissues are bluish-purple in color and very moist.
- Proestrus - Vagina is gaping and the tissues are reddish-pink and moist. Numerous longitudinal folds or striations are visible on both the dorsal and ventral lips.
- Estrus - Vaginal signs are similar to proestrus, but the tissues are lighter pink and less moist, and the striations are more pronounced.
- Metestrus-1 - Vaginal tissues are pale and dry. Dorsal lip is not as edematous as in estrus.
- Metestrus-2 - Vaginal signs are similar to metestrus-1, but the lip is less edematous and has receded. Whitish cellular debris may line the inner walls or partially fill the Vagina.
- Links: Mouse Estrous Cycle
Pig Estrous Cycle
The feedback systems between the ovaries, uterus, hypothalamus and pituitary gland govern a cycle of events that takes 18-21 days. If conception occurs this cyclic pattern is interrupted and pregnancy is maintained for approximately 114 days. Removal of the sucking stimulus at weaning triggers a new sequence of events.
Dog Estrous Cycle
- Proestrus (9 days) - Precedes estrus, estradiol concentration increases as ovarian follicules mature and the uterus enlarges. The vaginal epithelium proliferates accompanied by diapedesis of erythrocytes (most cells in vaginal smear) from uterine capillaries.
- Estrus (9 days) - Accompanied by female mating behaviour, glandular secretions increase, the vaginal epithelium becomes hyperemic, and ovulation occurs. Cycle is influenced mainly by estrogens and the interval between successive estrus cycles is about 7 months.
- Diestrus (70-80 days) - Accompanied by female non-mating behaviour, corpus lutea present and secretes progesterone. Uterine glands undergo hypertrophy and hyperplasia, vaginal secretions and the cervix constricts.
- Anestrus - Anestrus is a prolonged period of sexual rest where the reproductive system is quiescent.
- Links: Dog Development
Bovine Estrous Cycle
Specific hormone concentrations are not shown in the above graph, only the relative hormone levels at different times during the cycle.
- Links: Bovine Development
- Padmasana Singh, Amitabh Krishna, Rajagopala Sridaran Changes in bradykinin and bradykinin B(2)-receptor during estrous cycle of mouse. Acta Histochem.: 2011, 113(4);436-41 PMID:20546864
- A K Champlin, D L Dorr, A H Gates Determining the stage of the estrous cycle in the mouse by the appearance of the vagina. Biol. Reprod.: 1973, 8(4);491-4 PMID:4736343
C H Hubscher, D L Brooks, J R Johnson A quantitative method for assessing stages of the rat estrous cycle. Biotech Histochem: 2005, 80(2);79-87 PMID:16195173
Pei Su, Joyce C Wu, Jeffrey R Sommer, A Jesse Gore, Robert M Petters, William L Miller Conditional induction of ovulation in mice. Biol. Reprod.: 2005, 73(4);681-7 PMID:15917351
A K Champlin, D L Dorr, A H Gates Determining the stage of the estrous cycle in the mouse by the appearance of the vagina. Biol. Reprod.: 1973, 8(4);491-4 PMID:4736343
External Links Notice - The dynamic nature of the internet may mean that some of these listed links may no longer function. If the link no longer works search the web with the link text or name.
- Animal Development: Axolotl | Bat | Cat | Chicken | Cow | Dog | Dolphin | Echidna | Fly | Frog | Grasshopper | Guinea Pig | Hamster | Kangaroo | Koala | Lizard | Medaka | Mouse | Pig | Platypus | Rabbit | Rat | Sea Squirt | Sea Urchin | Sheep | Worm | Zebrafish | Life Cycles | Development Timetable | K12
- A | B | C | D | E | F | G | H | I | J | K | L | M | N | O | P | Q | R | S | T | U | V | W | X | Y | Z | Numbers | Symbols
Cite this page: Hill, M.A. (2014) Embryology Estrous Cycle. Retrieved July 24, 2014, from //embryology.med.unsw.edu.au/embryology/index.php?title=Estrous_Cycle
- Dr Mark Hill 2014, UNSW Embryology ISBN: 978 0 7334 2609 4 - UNSW CRICOS Provider Code No. 00098G