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Bentz AB, Thomas GWC, Rusch DB, Rosvall KA. Tissue-specific expression profiles and positive selection analysis in the tree swallow (Tachycineta bicolor) using a de novo transcriptome assembly. Sci Rep 2019; 9:15849. [PMID: 31676844 PMCID: PMC6825141 DOI: 10.1038/s41598-019-52312-4] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2019] [Accepted: 10/09/2019] [Indexed: 12/17/2022] Open
Abstract
Tree swallows (Tachycineta bicolor) are one of the most commonly studied wild birds in North America. They have advanced numerous research areas, including life history, physiology, and organismal responses to global change; however, transcriptomic resources are scarce. To further advance the utility of this system for biologists across disciplines, we generated a transcriptome for the tree swallow using six tissues (brain, blood, ovary, spleen, liver, and muscle) collected from breeding females. We de novo assembled 207,739 transcripts, which we aligned to 14,717 high confidence protein-coding genes. We then characterized each tissue with regard to its unique genes and processes and applied this transcriptome to two fundamental questions in evolutionary biology and endocrinology. First, we analyzed 3,015 single-copy orthologs and identified 46 genes under positive selection in the tree swallow lineage, including those with putative links to adaptations in this species. Second, we analyzed tissue-specific expression patterns of genes involved in sex steroidogenesis and processing. Enzymes capable of synthesizing these behaviorally relevant hormones were largely limited to the ovary, whereas steroid binding genes were found in nearly all other tissues, highlighting the potential for local regulation of sex steroid-mediated traits. These analyses provide new insights into potential sources of phenotypic variation in a free-living female bird and advance our understanding of fundamental questions in evolutionary and organismal biology.
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Affiliation(s)
- Alexandra B Bentz
- Department of Biology, Indiana University, Bloomington, IN, 47405, USA. .,Center for the Integrative Study of Animal Behavior, Indiana University, Bloomington, IN, 47405, USA.
| | - Gregg W C Thomas
- Department of Biology, Indiana University, Bloomington, IN, 47405, USA.,Department of Computer Science, Indiana University, Bloomington, IN, 47405, USA
| | - Douglas B Rusch
- Department of Biology, Indiana University, Bloomington, IN, 47405, USA.,Center for Genomics and Bioinformatics, Indiana University, Bloomington, IN, 47405, USA
| | - Kimberly A Rosvall
- Department of Biology, Indiana University, Bloomington, IN, 47405, USA.,Center for the Integrative Study of Animal Behavior, Indiana University, Bloomington, IN, 47405, USA
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Brzęk P, Kohl KD, Caviedes-Vidal E, Karasov WH. Fully reversible phenotypic plasticity of digestive physiology in young house sparrows: lack of long-term effect of early diet composition. J Exp Biol 2011; 214:2755-60. [DOI: 10.1242/jeb.058727] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
SUMMARY
Feeding conditions during the nestling period may significantly affect whole-life fitness in altricial birds but little is known about the physiological mechanisms responsible for these effects. Permanent changes (irreversible developmental plasticity) in digestive physiology caused by the neonatal diet may form such a mechanism. We previously showed that the lack of starch in the diet of house sparrow (Passer domesticus) nestlings between 3 and 12 days post-hatching significantly decreased the activity of intestinal maltase, an enzyme essential for starch digestion. To check whether diet-induced variation in maltase activity in young house sparrows is reversible, we raised them under laboratory conditions from 3 until 30 days of age on diets with either 0% starch or 25% starch, with some individuals experiencing a switch in their assigned diet at 12 days of age. We found evidence for the presence of an internal, presumably genetic, program for changes in the activity of maltase and sucrase, which was, however, significantly affected by diet composition (i.e. environmental factor). Digestive enzyme activity in 30 day old birds was not influenced by diet composition prior to day 12 but instead depended only on diet that was fed between days 12 and 30. We conclude that plasticity in the activity of intestinal disaccharidases in house sparrow nestlings represents completely reversible phenotypic flexibility that can help young sparrows to cope with unpredictable variation in food composition during ontogeny without long-term effects on their digestive system. However, comparison with other species suggests that the magnitude of digestive flexibility in young passerines may be evolutionarily matched to species-specific variation in feeding conditions.
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Affiliation(s)
- Paweł Brzęk
- Department of Forest and Wildlife Ecology, University of Wisconsin, 1630 Linden Drive, Madison, WI 53706, USA
| | - Kevin D. Kohl
- Department of Forest and Wildlife Ecology, University of Wisconsin, 1630 Linden Drive, Madison, WI 53706, USA
| | - Enrique Caviedes-Vidal
- Department of Forest and Wildlife Ecology, University of Wisconsin, 1630 Linden Drive, Madison, WI 53706, USA
- Laboratorio de Biología `Professor E. Caviedes Codelia', Facultad de Ciencias Humanas, and Departamento de Bioquímica y Ciencias Biológicas, Facultad de Química, Bioquímica y Farmacia, Universidad Nacional de San Luis, 5700 San Luis, Argentina
- Instituto Multidisciplinario de Investigaciones Biológicas de San Luis, Consejo Nacional de Investigaciones Científicas y Técnicas, 5700 San Luis, Argentina
| | - William H. Karasov
- Department of Forest and Wildlife Ecology, University of Wisconsin, 1630 Linden Drive, Madison, WI 53706, USA
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Brzęk P, Kohl K, Caviedes-Vidal E, Karasov WH. Developmental adjustments of house sparrow (Passer domesticus)nestlings to diet composition. J Exp Biol 2009; 212:1284-93. [DOI: 10.1242/jeb.023911] [Citation(s) in RCA: 49] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
SUMMARY
House sparrow nestlings are fed primarily on insects during the first 3 days of their life, and seeds become gradually more important afterwards. We tested whether developmental changes in size and functional capacity of the digestive tract in young house sparrows are genetically hard-wired and independent of diet, or can be modified by food type. Under laboratory conditions, we hand-fed young house sparrows with either a starch-free insect-like diet, based mainly on protein and fat, or a starch-containing diet with a mix of substrates similar to that offered to older nestlings in natural nests when they are gradually weaned from an insect to a seed diet. Patterns of overall development in body size and thermoregulatory ability, and in alimentary organ size increase, were relatively similar in house sparrow nestlings developing on both diets. However, total intestinal maltase activity, important in carbohydrate breakdown, was at least twice as high in house sparrow nestlings fed the starch-containing diet (P<0.001). The change in maltase activity of nestlings was specific, as no change occurred in aminopeptidase-N activity in the same tissues. There was no significant diet effect on digesta retention time, but assimilation efficiency for radiolabeled starch tended to be higher (P=0.054) in nestlings raised on starch-containing diet. Future studies must test whether the diet-dependent increase in maltase activity during development is irreversible or reversible, reflecting, respectively, a developmental plasticity or a phenotypic flexibility.
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Affiliation(s)
- Paweł Brzęk
- Department of Forest and Wildlife Ecology, University of Wisconsin, 1630 Linden Drive, Madison, WI 53706, USA
| | - Kevin Kohl
- Department of Forest and Wildlife Ecology, University of Wisconsin, 1630 Linden Drive, Madison, WI 53706, USA
| | - Enrique Caviedes-Vidal
- Laboratorio de Biología “Professor E. Caviedes Codelia”,Facultad de Ciencias Humanas, and Departamento de Bioquímica y Ciencias Biológicas, Universidad Nacional de San Luis, 5700–San Luis,Argentina
- IMIBIO-SL CONICET, 5700–San Luis, Argentina
| | - William H. Karasov
- Department of Forest and Wildlife Ecology, University of Wisconsin, 1630 Linden Drive, Madison, WI 53706, USA
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Brzek P, Konarzewski M. Relationship between avian growth rate and immune response depends on food availability. ACTA ACUST UNITED AC 2007; 210:2361-7. [PMID: 17575041 DOI: 10.1242/jeb.003517] [Citation(s) in RCA: 74] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Life history theory predicts that when resources are limited growing organisms are likely to trade an immune response for competing demands of growth. To test this we examined the effect of energy intake on body mass increments and an immune response in hand-reared sand martin (Riparia riparia) nestlings. We subjected the nestlings to three different feeding regimes, mimicking the range of food availability in the wild, and then evaluated nestlings' immune response to phytohaemagglutinin (PHA). Direction of correlation between the magnitude of PHA-induced swelling response and body mass increments depended on food availability: it was negative when food was scarce and positive when resources were plentiful. There was no significant correlation between the two traits under intermediate feeding conditions. We conclude that the relative cost of immune function in young birds depends on food availability and, therefore, may be modified by external factors such as weather conditions or hatching asynchrony.
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Affiliation(s)
- Paweł Brzek
- Department of Animal Ecology, University of Białystok, Swierkowa 20B, 15-950 Białystok, Poland.
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