The Study Of Mate Choice And Molecular Mechanism In Padda Oryzivora

Mate choice is one of the most important aspects of sexual selection.Uncovering the underlying mechanisms of mate choice is a central issue in sexual selection studies. Females choose high-quality males as mates to obtain direct benefits, such as resources, nutrition, and protection. Furthermore, they can acquire indirect genetic benefits for future generations. Further studies of female mate choice would improve our understanding of sexual selection and evolutionary processes. Here, I investigated the effects of body characteristics, male song and the presence of male audience on mate choice in Padda oryzivora.Body characteristics are important factors influencing the mate choice in birds. Some body characteristics can reliably reflect the males’quality. In general, only healthy individuals in the population are able to maximize the expression of these features. Males with good body characteristics will get more mating opportunities. We measured some body characteristics of male Padda oryzivora, including body mass, wing length, tail length, tarsometatarsal length, beak length, and beak thickness. We explored the influence of body characteristics of male birds to mate choice, using two-way choice, using two male birds to stimulate the female, in order to observe the female preference for the male on both ends. The results showed that the beak thickness is an important character in determining the preference of females. The females preferred males with thicker beak.Most animals live in an information network, where individuals can "eavesdrop" useful information, such as the vitality, status and quality of competitors and potential mates. Male has the "eavesdropping" behavior from male-male phenomenon to gather information in the competition. Female could evaluate the quality of potential mates by "eavesdropping" in the early mate choice stage. Similarly, under the female "audience effect", the male can also adjust their behavior appropriately according to different conditions of "audience", such as hiding their extra-pair behavior, but will strengthen their competition behavior so as to safeguard their own interests. I explored the influence of male "audience effect" to the mate choice, observing the competition behavior among females under different conditions, including that audience is absent, the audience is familiar with the male, and the spouse is audience. I found that female aggressive behavior was highest under the condition that the spouse is audience, and significantly higher than the audience is familiar with the male. The behavior under above-mentioned two conditions was significantly higher than that at the absence of audience. Results from the present study indicated that female Padda oryzivora can make appropriate adjustments for female-female competitive behavior based on different audience.Bird song plays an important role in the process of mate choice as a kind of courting signal. Bird song is a reliable indicator of the male quality, which is useful for female to choose excellent mate for improving reproductive success and get better offspring. Thus, such a behavior would benefit for the evolution and the continuation of race. Previous studies found that females preferred males having more complex song. I examined the influence of the source and type of birds song to mate choice, using two-way choice, singing with a spouse lovebird (courtship or non-courtship singing) and a non-spouse lovebird (courtship or non-courtship singing) to stimulate the female, in order to observe the female preference for the singing on both ends. Results showed that the courtship singing and the non-courtship singing both had the function of individual identification. In contrast, only the courtship singing had functions of courtship, with the effect of attracting females. Such a result suggests that the courtship singing had stronger influence on female mate choice and may plat a role in extra-pair mating. In order to further understand whether the Padda oryzivora chirp perception is similar to human perceptions, I compared the different music preference of female Padda oryzivora. I found female Padda oryzivora preferred classical or modern music to white noise, and preferred modern music to classical music. Therefore, we suggested that female Padda oryzivora was able to perceive and discern music, which maybe had certain similarities to the human voice in perception resolution mechanism.To inquire into the molecular mechanisms underlying how birds song influence mate choice, I focused on the key gene referred to birds song of perception—ZENK gene. I examined its expression at CMM(the caudomedial mesopallium) segment in the brain of female Padda oryzivora. Based on the foregoing tape,Format Factory software was used to edit two kinds of songs, sexy song and non-sexual song, respectively. Using two-way choice and evaluating the different music preference of female Padda oryzivora, I found that female Padda oryzivora preferred sexy songs. Editorial songs were used to stimulate female in order to observe expression of ZENK gene at CMM segment. Immunohistochemical results showed that the ZENK gene had higher levels of expression under sexy songs’ stimulation. I suspect that the sexy songs reflected high sound quality and could provoke the expression of ZENK gene. In the process of mate choice, the expression of ZENK gene in the CMM played a vital role for the female to distinguish the quality of males’ songs.