Reproduction/reproductive behavior

Organisms evolving under aimual temperature cycles and in environments with varying temperatures spatially have incorporated thermal cues in reproductive behavior, habitat selection, and certain other features which act at the population level. Thus, the balance of births and mortaUties, which determines whether a species survives, is akin to the metaboHc balance at the physiological level in being dependent upon the match, within certain limits, to prescribed temperatures at different times of year. At the ecosystem level, relationships among species, eg, predators, competitors, prey animals, and plant foods, are related to environmental temperatures in complex ways. Many of these interactions are poorly understood. 

Androgens, represented by testosterone, are male sex hormones involved in reproduction, behavior, and bone and muscle growth. 

PATISAUL H B, DiNDO M, WHITTEN p L, YOUNG L J (2001) Soy isoflavone Supplements antagonize reproductive behavior and oestrogen receptor alpha- and beta-dependent gene expression in the brain. Endocrinol. 142 2946-52. 

Newman S. (1999). The medial extended amygdala in male reproductive behavior — a node in the mammalian social behavior network. Ann NY Acad Sci 877, 242-257. 

Gardiner, C.H. (1976) Habit and reproductive behavior of Trichinella spiralis. Journal of Parasitology 62, 865—870. 

The queen is usually reproductively dominant within the colony and uses chemical cues as both primer and releaser pheromones to suppress the production or fecundity of other sexuals, inhibit reproduction by worker castes, modulate reproductive behaviors (e.g., inhibit swarming and orient swarms), attract males, regulate worker tasks and worker ontogeny, and produce host repellents in slave-making species. Considering the importance of queen semiochemicals in social hymenoptera, few queen pheromones have been chemically identified. The queens of most social hymenopteran colonies are attractive to workers, allowing them to be properly tended as well as to facilitate the dissemination of other pheromone cues. However, the retinue pheromone has been chemically identified in very few species. In the 1980s, queen pheromone components were identified in the fire ant, Solenopsis invicta [91,92], and in the Pharaoh s ant, Monomoriumpharaonis [93]. 

So far, the best understood examples of genomic regulation of neuronal function stem from the actions of gonadal and adrenal steroids and thyroid hormone, and many of these actions are involved in the plasticity of behavior that results from hormonal secretion, such as changes in aggressive and reproductive behavior and... 

Sauther, M. (1991) Reproductive behavior of free-ranging Lemur catta at Beza Mahafaly special reserve, Madagascar. Am. J. Phys. Anthropol. 84, 463 177. 

Gerrits, P. O. and Holstege, G. (1999) Descending projections from the nucleus retroambiguus to the iliopsoas motoneuronal cell groups in the female golden hamster possible role in reproductive behavior. J. Comp. Neurol. 403, 219-28. 

Abstract Mate recognition is an essential component of successful reproductive behavior, and in rodent species, is primarily guided by the perception of social odors in the environment. Importantly, there is substantial evidence that species or sexual odor preferences may be regulated by early olfactory experience, although considerable variability in the plasticity of these behaviors has been observed. The current chapter summarizes what is known regarding the role of early olfactory experience in the development of adult odor preferences, synthesizing data across species, sex, and behavioral paradigms. 

Successful reproductive behavior relies on the ability to identify and approach appropriate mating partners within the environment. Critically, mate recognition requires identifying species and sex characteristics of possible mates. As in many mammalian species, rodents use odor cues as the primary mechanism for mate recognition (Johnston 1983). Thus, sexually mature rodents typically display strong behavioral preferences for conspecific odors from opposite-sex individuals compared to odors from the same-sex or heterospecific individuals (Johnston 1983). 

Taken together, this body of work demonstrates that adult behavioral responses to social odors are shaped by early olfactory experience. Indeed, heterospecific or artificial odor cues associated with the rearing environment acquire attractive properties that can last into adulthood in many rodent species. Furthermore, early experience with opposite-sex odors appears to be critical for the normal development of appropriate behavioral responses to sexual odors in mice and hamsters. Importantly, the behavioral plasticity observed using these different experimental approaches may all be mediated by a classical conditioning model of olfactory learning. The experience-dependent development of odor preference in rodents therefore provides a powerful model for understanding how the olfactory system recognizes and learns the salience of social odors, a function that is critical for the appropriate expression of reproductive behavior. 

Johnston, R. E. (1983) Chemical signals and reproductive behavior. In J. G. Vandenbergh (Ed.), Pheromones and Reproduction in Mammals. Academic Press, New York, pp. 3-37. 

Choi, G. B., Dong, H.W., Murphy, A.J. Valenzuela, D.M., Yancopoulos, G.D., Swanson, L.W. and Anderson, D.J. (2005) Lhx6 delineates a pathway mediating innate reproductive behaviors from the amygdala to the hypothalamus. Neuron 46, 647-60. 

Pfaff, D. W., Schwartz-Giblin, S, McCarthy, M. M., and Kow, L.-M. 1994. Cellular and molecular mechanisms of female reproductive behaviors. In The Physiology of Reproduction. Second Edition. Ed. E. Knobil and J. D. Neill. New York Raven Press, pp. 107 220. 

The list of pheromone controls on reproductive behavior can be extended female pheromones inhibit estrus in adult females and delay puberty in juvenile females, Lee-Boot effect male pheromones can block pregnancy, Bruce effect pheromones from dominant females can suppress reproduction in subordinate females and so on. Have a look at Wyatt s book for an abundance of examples. 

In the past few years the use of rotifers in ecotoxicological studies has substantially increased. The main endpoints used are mortality, reproduction, behavior, cellular biomarkers, mesocosms, and species diversity in natural populations [126]. Several workers have used Brachionus calyciflorus for various types of toxicity assessments. Thus, comprehensive evaluation of approximately 400 environmental samples for the toxicity assessment of solid waste elutriates, monitoring wells, effluents, sediment pore water, and sewage sludge was carried out by Persoone and Janssen [127]. The mortality of rotifers hatched from cysts is evaluated after 24 hours exposure. This microbiotest has been commercialized in a Rotoxkit F [128,129]. 

Aquatic animals use their chemical senses in all aspects of their lives, from reproductive behavior to feeding, habitat selection, and predator avoidance. The hydrodynamic properties determine the possibilities and limits of chemical communication in water. As a medium, water is as dynamic as air, so that convection and advection are far more important for odor transport than is diffusion. Distribution by currents is even more important in water because compounds of similar molecular weight diffuse four orders of magnitude more slowly than in air (Gleeson, 1978). Diffusion of odorants may be important only in the submillimeter range, while turbulence is typical for water masses above the centimeter range. 

To discriminate diet-dependent odors can be vital in the context of reproductive behavior. Supporting the hypothesis that animals discriminate and prefer potential mates that are in good nutritional condition, Ferkin et ah (1997) showed that meadow voles preferred odors of members of their own species that are on a high-protein diet (Table 3.2). 

In the golden hamster, the VNO is essential for certain reproductive behaviors, while the main olfactory system mediates responses that involve species recognition (Johnston, 1992 Table 5.2). As in mice, removal of the VNO impairs sexual behavior in male golden hamsters, but only if carried out before the animal had had sexual experience (Meredith, 1986). The same is true for ultrasonic vocalizations. 

Discrimination of the own species from other closely related and sym-patric species is essential not only for reproductive behavior hut also in the contexts of competition for resources and antipredator behavior. 

Chemical cues attract the sexes and modulate sexual behavior in many or most mammal species. Chemical signals also often reveal the quality and reproductive potential of individuals. In addition to chemical cues, multiple cues in different sensory modalities guide the complex reproductive behavior of mammals. 

Andren, C. (1982). The role of the vomeronasal organs in the reproductive behavior of the adder Viperherus. Copeia 1982,148-157. 

Chien, A. K. (1973). Reproductive behavior of the angelfish Pterophyllum scalare (Pisces Cichlidae) II. Influence of male stimuli upon the spawning rate of females. Animal Behaviour 21,457-463. 

Keverne, E. B. (1983). Chemical communication and reproductive behavior primates. In... 

One dose level is tested, usually the higjiest dose associated with the production of minimal toxic effects, but without affecting reproductive behavior or survival. To establish a dose—response relationship, two additional lower doses are required. 

Abnormalities associated with survival, reproductive behavior, secondary sex characteristics, histopathology, and fecundity (i.e., number of spawns, number of eggs/spawn, fertility, and development of offspring)... 

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