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Biological Sciences Faculty Research and Publications

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The Discovery Of Xy Sex Chromosomes In A Boa And Python, Tony Gamble, Todd A. Castoe, Stuart V. Nielsen, Jason L. Banks, Daren C. Card, Drew R. Schield, Gordon W. Schuett, Warren Booth Jul 2017

The Discovery Of Xy Sex Chromosomes In A Boa And Python, Tony Gamble, Todd A. Castoe, Stuart V. Nielsen, Jason L. Banks, Daren C. Card, Drew R. Schield, Gordon W. Schuett, Warren Booth

Biological Sciences Faculty Research and Publications

For over 50 years, biologists have accepted that all extant snakes share the same ZW sex chromosomes derived from a common ancestor [1, 2, 3], with different species exhibiting sex chromosomes at varying stages of differentiation. Accordingly, snakes have been a well-studied model for sex chromosome evolution in animals [1, 4]. A review of the literature, however, reveals no compelling support that boas and pythons possess ZW sex chromosomes [2, 5]. Furthermore, phylogenetic patterns of facultative parthenogenesis in snakes and a sex-linked color mutation in the ball python (Python regius) are best explained by boas …


The Urea Carboxylase And Allophanate Hydrolase Activities Of Urea Amidolyase Are Functionally Independent, Yi Lin, Cody J. Boese, Martin St. Maurice Oct 2016

The Urea Carboxylase And Allophanate Hydrolase Activities Of Urea Amidolyase Are Functionally Independent, Yi Lin, Cody J. Boese, Martin St. Maurice

Biological Sciences Faculty Research and Publications

Urea amidolyase (UAL) is a multifunctional biotin-dependent enzyme that contributes to both bacterial and fungal pathogenicity by catalyzing the ATP-dependent cleavage of urea into ammonia and CO2. UAL is comprised of two enzymatic components: urea carboxylase (UC) and allophanate hydrolase (AH). These enzyme activities are encoded on separate but proximally related genes in prokaryotes while, in most fungi, they are encoded by a single gene that produces a fusion enzyme on a single polypeptide chain. It is unclear whether the UC and AH activities are connected through substrate channeling or other forms of direct communication. Here, we use …


Restriction Site-Associated Dna Sequencing (Rad-Seq) Reveals An Extraordinary Number Of Transitions Among Gecko Sex-Determining Systems, Tony Gamble, Jessi Coryell, Tariq Ezaz, Joshua Lynch May 2015

Restriction Site-Associated Dna Sequencing (Rad-Seq) Reveals An Extraordinary Number Of Transitions Among Gecko Sex-Determining Systems, Tony Gamble, Jessi Coryell, Tariq Ezaz, Joshua Lynch

Biological Sciences Faculty Research and Publications

Sex chromosomes have evolved many times in animals and studying these replicate evolutionary “experiments” can help broaden our understanding of the general forces driving the origin and evolution of sex chromosomes. However this plan of study has been hindered by the inability to identify the sex chromosome systems in the large number of species with cryptic, homomorphic sex chromosomes. Restriction site-associated DNA sequencing (RAD-seq) is a critical enabling technology that can identify the sex chromosome systems in many species where traditional cytogenetic methods have failed. Using newly generated RAD-seq data from 12 gecko species, along with data from the literature, …


The Ecology Of Lianas And Their Role In Forests, Stefan A. Schnitzer, Frans Bongers May 2002

The Ecology Of Lianas And Their Role In Forests, Stefan A. Schnitzer, Frans Bongers

Biological Sciences Faculty Research and Publications

Recent studies have demonstrated the increasingly important role of lianas (woody vines) in forest regeneration, species diversity and ecosystem-level processes, particularly in the tropics. Mechanisms responsible for the maintenance of liana species diversity could yield new insights into the maintenance of overall species diversity. Lianas contribute to forest regeneration and competition, not only by competing directly with trees, but also by differentially affecting tree species and thus changing how trees compete among themselves. In addition, they contribute considerably to ecosystem-level processes, such as whole-forest transpiration and carbon sequestration. As the rate of tropical forest disturbance increases, they are likely to …