PMC:17597 / 1887-3982 JSONTXT

{"project":"2_test","denotations":[{"id":"11178278-10318926-44706684","span":{"begin":421,"end":422},"obj":"10318926"},{"id":"11178278-9673848-44706685","span":{"begin":653,"end":654},"obj":"9673848"},{"id":"11178278-10318926-44706686","span":{"begin":874,"end":875},"obj":"10318926"},{"id":"11178278-10085265-44706687","span":{"begin":876,"end":877},"obj":"10085265"},{"id":"11178278-10318926-44706688","span":{"begin":934,"end":935},"obj":"10318926"},{"id":"11178278-10591654-44706689","span":{"begin":1181,"end":1182},"obj":"10591654"},{"id":"11178278-11135302-44706690","span":{"begin":1888,"end":1889},"obj":"11135302"}],"text":"Background\nSocial insect colonies are defined in part by reproductive division of labor, whereby some colony members are considerably more fecund than others. The reproductive roles of colony members often are fixed by events that occur during larval development. An understanding of the mechanisms behind role, or caste, determination allows tests of several models for the evolution and maintenance of social life [1,2,3]. Female honeybees (Apis mellifera) are fated to become queens or workers during the first few days of larval development. Despite detailed knowledge of the physiological differences between workers and queens during development [4], relatively little is known of the underlying genetic machinery that drives these changes. Although differences in honeybee larval transcription had been inferred [5], caste-biased genes were identified only recently [3,6,7]. On the basis of inferred homology with known genes [3], these genes appear to be involved with diverse metabolic, nutritional and signaling processes during development.\nGene-expression arrays provide a powerful new tool to clarify the timing and nature of genetic events during insect development [8]. Here we use this technique to explore the genetic mechanisms of divergence between social insect castes. We contrast the gene-expression patterns of worker-destined and queen-destined larvae and then compare both castes with younger, bipotential, individuals. These comparisons allow tests of hypotheses concerning the evolutionary relationship between queen- or worker-destined developmental pathways in social insects (see, for example, [2]). More generally, changes in gene expression during insect caste determination can shed light on diverse developmental events such as differences in hormonal titers, the development or apoptosis of reproductive tissues, and developmental rates and metabolism [9]. We present evidence for widespread divergence in gene expression between workers and queens, and identify particular genes that appear to be integral to the production of these distinct adult phenotypes."}

{"project":"Colil","denotations":[{"id":"T1","span":{"begin":934,"end":935},"obj":"10318926"},{"id":"T2","span":{"begin":874,"end":875},"obj":"10318926"},{"id":"T3","span":{"begin":876,"end":877},"obj":"10085265"},{"id":"T4","span":{"begin":421,"end":422},"obj":"10318926"},{"id":"T5","span":{"begin":653,"end":654},"obj":"9673848"},{"id":"T6","span":{"begin":1181,"end":1182},"obj":"10591654"},{"id":"T7","span":{"begin":1888,"end":1889},"obj":"11135302"}],"namespaces":[{"prefix":"_base","uri":"http://pubannotation.org/docs/sourcedb/PubMed/sourceid/"}],"text":"Background\nSocial insect colonies are defined in part by reproductive division of labor, whereby some colony members are considerably more fecund than others. The reproductive roles of colony members often are fixed by events that occur during larval development. An understanding of the mechanisms behind role, or caste, determination allows tests of several models for the evolution and maintenance of social life [1,2,3]. Female honeybees (Apis mellifera) are fated to become queens or workers during the first few days of larval development. Despite detailed knowledge of the physiological differences between workers and queens during development [4], relatively little is known of the underlying genetic machinery that drives these changes. Although differences in honeybee larval transcription had been inferred [5], caste-biased genes were identified only recently [3,6,7]. On the basis of inferred homology with known genes [3], these genes appear to be involved with diverse metabolic, nutritional and signaling processes during development.\nGene-expression arrays provide a powerful new tool to clarify the timing and nature of genetic events during insect development [8]. Here we use this technique to explore the genetic mechanisms of divergence between social insect castes. We contrast the gene-expression patterns of worker-destined and queen-destined larvae and then compare both castes with younger, bipotential, individuals. These comparisons allow tests of hypotheses concerning the evolutionary relationship between queen- or worker-destined developmental pathways in social insects (see, for example, [2]). More generally, changes in gene expression during insect caste determination can shed light on diverse developmental events such as differences in hormonal titers, the development or apoptosis of reproductive tissues, and developmental rates and metabolism [9]. We present evidence for widespread divergence in gene expression between workers and queens, and identify particular genes that appear to be integral to the production of these distinct adult phenotypes."}