Chilton, N. B. (2004). The use of nuclear ribosomal DNA markers for the identification of bursate nematodes (order Strongylida) and for the diagnosis of infections. Anim Health Res Rev, 5(2), 173–187.
Abstract: Many bursate nematodes are of major importance to animal health. Animals are often parasitized by multiple species that differ in their prevalence, relative abundance and/or pathogenicity. Implementation of effective management strategies for these parasites requires reliable methods for their detection in hosts, identification to the species level and measurement of intensity of infection. One major problem is the difficulty of accurately identifying and distinguishing many species of bursate nematode because of the remarkable morphological similarity of their eggs and larvae. The inability to identify, with confidence, individual nematodes (irrespective of their life-cycle stage) to the species level by morphological methods has often led to a search for species-specific genetic markers. Studies over the past 15 years have shown that sequences of the internal transcribed spacers of ribosomal DNA provide useful genetic markers, providing the basis for the development of PCR-based diagnostic tools. Such molecular methods represent powerful tools for studying the systematics, epidemiology and ecology of bursate nematodes and, importantly, for the specific diagnosis of infections in animals and humans, thus contributing to improved control and prevention strategies for these parasites.
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Yokoyama, S., & Radlwimmer, F. B. (1999). The molecular genetics of red and green color vision in mammals. Genetics, 153(2), 919–932.
Abstract: To elucidate the molecular mechanisms of red-green color vision in mammals, we have cloned and sequenced the red and green opsin cDNAs of cat (Felis catus), horse (Equus caballus), gray squirrel (Sciurus carolinensis), white-tailed deer (Odocoileus virginianus), and guinea pig (Cavia porcellus). These opsins were expressed in COS1 cells and reconstituted with 11-cis-retinal. The purified visual pigments of the cat, horse, squirrel, deer, and guinea pig have lambdamax values at 553, 545, 532, 531, and 516 nm, respectively, which are precise to within +/-1 nm. We also regenerated the “true” red pigment of goldfish (Carassius auratus), which has a lambdamax value at 559 +/- 4 nm. Multiple linear regression analyses show that S180A, H197Y, Y277F, T285A, and A308S shift the lambdamax values of the red and green pigments in mammals toward blue by 7, 28, 7, 15, and 16 nm, respectively, and the reverse amino acid changes toward red by the same extents. The additive effects of these amino acid changes fully explain the red-green color vision in a wide range of mammalian species, goldfish, American chameleon (Anolis carolinensis), and pigeon (Columba livia).
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Weiss, A., King, J. E., & Figueredo, A. J. (2000). The heritability of personality factors in chimpanzees (Pan troglodytes). Behav Genet, 30(3), 213–221.
Abstract: Human personality and behavior genetic studies have resulted in a growing consensus that five heritable factors account for most variance in human personality. Prior research showed that chimpanzee personality is composed of a dominance-related factor and five human-like factors--Surgency, Dependability, Emotional Stability, Agreeableness, and Openness. Genetic, shared zoo, and nonshared environmental variance components of the six factors were estimated by regressing squared phenotypic differences of all possible pairs of chimpanzees onto 1 – Rij, where Rij equals the degree of relationship and a variable indicating whether the pair was housed in the same zoo. Dominance showed significant narrow-sense heritability. Shared zoo effects accounted for only a negligible proportion of the variance for all factors.
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Morley, K. I., & Montgomery, G. W. (2001). The genetics of cognitive processes: candidate genes in humans and animals. Behav Genet, 31(6), 511–531.
Abstract: It has been hypothesized that numerous genes contribute to individual variation in human cognition. An extensive search of the scientific literature was undertaken to identify candidate genes which might contribute to this complex trait. A list of over 150 candidate genes that may influence some aspect of cognition was compiled. Some genes are particularly strong candidates based on evidence for involvement in cognitive processes in humans, mice, and Drosophila melanogaster. This survey confirms that many genes are associated with cognitive variation and highlights the potential importance of animal models in the study of human cognition.
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Hamilton, W. D. (1964). The genetical evolution of social behaviour. I. J. Theor. Biol., 7(1and 2), 1–52.
Abstract: A genetical mathematical model is described which allows for interactions between relatives on one another's fitness. Making use of Wright's Coefficient of Relationship as the measure of the proportion of replica genes in a relative, a quantity is found which incorporates the maximizing property of Darwinian fitness. This quantity is named “inclusive fitness”. Species following the model should tend to evolve behaviour such that each organism appears to be attempting to maximize its inclusive fitness. This implies a limited restraint on selfish competitive behaviour and possibility of limited self-sacrifices.
Special cases of the model are used to show (a) that selection in the social situations newly covered tends to be slower than classical selection, (b) how in populations of rather non-dispersive organisms the model may apply to genes affecting dispersion, and (c) how it may apply approximately to competition between relatives, for example, within sibships. Some artificialities of the model are discussed.
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Nettle, D. (2006). The evolution of personality variation in humans and other animals. Am Psychol, 61(6), 622–631.
Abstract: A comprehensive evolutionary framework for understanding the maintenance of heritable behavioral variation in humans is yet to be developed. Some evolutionary psychologists have argued that heritable variation will not be found in important, fitness-relevant characteristics because of the winnowing effect of natural selection. This article propounds the opposite view. Heritable variation is ubiquitous in all species, and there are a number of frameworks for understanding its persistence. The author argues that each of the Big Five dimensions of human personality can be seen as the result of a trade-off between different fitness costs and benefits. As there is no unconditionally optimal value of these trade-offs, it is to be expected that genetic diversity will be retained in the population.
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de Waal, F. B. (1999). The end of nature versus nurture. Sci Am, 281(6), 94–99.
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Bannasch, D., Rinaldo, C., Millon, L., Latson, K., Spangler, T., Hubberty, S., et al. (2007). SRY negative 64,XX intersex phenotype in an American saddlebred horse. Vet J, 173(2), 437–439.
Abstract: A female American saddlebred horse was presented for surgical correction of a possible pseudohermaphrodite condition. The horse had abnormal external genitalia and exhibited stallion-like behaviour. No evidence of uterine or ovarian tissue was identified on laparoscopic examination, but hypoplastic testicular-like tissue was removed, although this was found to contain no spermatogonia upon histopathological examination. A karyotype was performed and showed the normal chromosomal complement for a female horse (64,XX). Polymerase chain reaction to detect the SRY gene was negative in peripheral blood as well as the testicular-like tissue. This case represents the first report of an SRY negative XX-male sex reversal intersex phenotype, which is a potentially inherited condition, in an American saddlebred horse.
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Traversa, D., Giangaspero, A., Galli, P., Paoletti, B., Otranto, D., & Gasser, R. B. (2004). Specific identification of Habronema microstoma and Habronema muscae (Spirurida, Habronematidae) by PCR using markers in ribosomal DNA. Mol Cell Probes, 18(4), 215–221.
Abstract: Gastric or cutaneous habronemosis caused by Habronema microstoma Creplin, 1849 and Habronema muscae Carter, 1865 is a parasitic disease of equids transmitted by muscid flies. There is a paucity of information on the epidemiology of this disease, which is mainly due to limitations with diagnosis in the live animal and with the identification of the parasites in the intermediate hosts. To overcome such limitations, a molecular approach, based on the use of genetic markers in the second internal transcribed spacer (ITS-2) of ribosomal DNA, was established for the two species of Habronema. Characterisation of the ITS-2 revealed sequence lengths and G+C contents of 296 bp and 29.5% for H. microstoma, and of 334 bp and 35.9% for H. muscae, respectively. Exploiting the sequence difference (approximately 40%) between the two species of nematode, primers were designed and tested by the polymerase chain reaction (PCR) for their specificity using a panel of control DNA samples from common equid endoparasites, and from host tissues, faeces or muscid flies. Effective amplification from each of the two species of Habronema was achieved from as little as 10 pg of genomic DNA. Hence, this molecular approach allows the specific identification and differentiation of the DNA from H. microstoma and H. muscae, and could thus provide a molecular tool for the specific detection of Habronema DNA (irrespective of developmental stage) from faeces, skin and muscid fly samples. The establishment of this tool has important implications for the specific diagnosis of clinical cases of gastric and cutaneous habronemosis in equids, and for studying the ecology and epidemiology of the two species of Habronema.
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Momozawa, Y., Takeuchi, Y., Tozaki, T., Kikusui, T., Hasegawa, T., Raudsepp, T., et al. (2007). SNP detection and radiation hybrid mapping in horses of nine candidate genes for temperament. Anim Genet, 38(1), 81–83.
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