Professor
Department of Biological Sciences
Towson University
Towson, MD 21252 USA
Office: Smith 213
Phone: 410-704-2035
Fax: 410-704-2405
email: bmasters@towson.edu
Courses Taught:
I have taught a number of courses since coming to Towson University. The courses I currently teach on a regular basis include:
· Cell Biology (BIOL 408)
· Molecular Ecology, Evolution and Conservation (BIOL 405)
· Molecular Ecology and Evolution (BIOL 612)
Research Interests:
My research interests involve the use of molecular genetic techniques to answer ecological and evolutionary questions. Since coming to Towson University, my students and I have been involved in research on a number of topics including the following:
· Parental behavior in salamanders
· Genetic structure of yellow perch and blue crab populations in the Chesapeake Bay
· Extra-pair mating behavior in house wrens, mountain bluebirds, and grasshopper sparrows
· Associations between genetic heterozygosity and fitness
· Molecular evolution of microsatellite sequences
We are currently starting a project in my lab examining population structure, heterozygosity-fitness correlations, molecular evolution of microsatellites, and mating behavior using a locally common species, the spotted salamander.
I am always interested in finding undergraduate and graduate students who are interested in working with me.
Selected Publications:
(Please contact me if you are interested in a copy of any of the papers discussed below.)
· Masters, B.S., L.S. Johnson, B.G.P. Johnson, J.L. Brubaker, S.K. Sakaluk and C.F. Thompson. 2010. Evidence for heterozygote instability in microsatellite loci in house wrens. Biology Letters. In press. (PDF available)
Microsatellites are repetitive, short sequences found in the genomes of every organism from bacteria to humans. They have been shown to play a role in cancer and a number of genetic diseases, as well as the evolution of organisms. Microsatellites have a high mutation rate, but the factors affecting those rates are not well understood. It has been proposed that heterozygosity may increase mutation rate, a process referred to as heterozygote instability. Our analysis of the inheritance of microsatellites in house wrens supports heterozygote instability, an observation with significant implications for understanding the mutation and evolution of these sequences. I intend to pursue this research further.
Forsman, A.M., L.A. Vogel, S.K. Sakaluk, B.G. Johnson, B.S. Masters, L.S. Johnson, and C.F. Thompson. 2008. Female house wrens (Troglodytes aedon) increase the size, but not the immunocompetence, of their offspring through extra-pair mating. Molecular Ecology. 17:3697-3706. (PDF available)
· Johnson, L.S., C.F. Thompson, S.K. Sakaluk, M. Neuhäuser, B.G.P. Johnson, S. S. Soukup, S. J. Forsythe and B.S. Masters. 2009. Extra-pair young in house wren broods are more likely to be male than female. Proceedings of the Royal Society of London B. 276:2285-2289. (PDF available)
· Johnson, L.S., J.L. Brubaker, B.G.P. Johnson and B.S. Masters. 2009. Evidence for a maternal effect benefiting extra-pair offspring in a songbird, the house wren (Troglodytes aedon). Journal of Avian Biology. 40:1-6. (PDF available)
These three papers are a part of research we have done in my laboratory on extra-pair mating behavior in birds. In the first paper, we found no evidence that the offspring of extra-pair males had more effective immune systems, but they did tend to be larger. We show in the second paper that extra-pair young tend to hatch earlier, which may account for their larger size. Interestingly, as we show in the third paper, while house wren nestlings overall are evenly divided between males and females, extra-pair young are significantly more likely to be male than female.
· Masters, B.S., B.G. Hicks, L.S. Johnson, and L.A. Erb. 2003. Genotype and extra-pair paternity in the house wren: a rare male effect? Proceedings of the Royal Society of London B. 270:1393-1397. (PDF available)
· Masters, B.S., L.S. Johnson, B.G. Johnson, C.J. Neely, and K.L. Williams. 2009. “Compatible alleles” and extra-pair paternity: conclusions depend on the microsatellite loci used. The Condor. 111(2):365-369. (PDF available)
In the first paper we present evidence that extra-pair sires are less genetically related to females than would be predicted by chance. This may have benefits since increased heterozygosity of offspring may be associated with higher fitness. We have found further evidence supporting this initial observation in a larger data set collected from another population of house wrens. In this recent research (which will be presented in a paper submitted for publication later this year), we found that extra-pair males were less related to females than would be predicted by chance, while within-pair males were not. We hypothesize that females are relatively non-selective when it comes to the genetic compatibility of pair-males, and are much more concerned with things like territory quality, since that is likely to have a much more significant impact on their offspring. However, territory quality of extra-pair males is unimportant to females because it is unlikely to have any impact on their offspring, so genetic compatibility becomes significant. As the second paper listed above demonstrates, it is important to pay attention to the technical details of genetic analysis when doing these types of studies.
I am currently writing a manuscript that describes extra-pair paternity in grasshopper sparrows. Our study population on Maryland’s eastern shore has a very high rate of extra-pair paternity, but females seem to mate with whatever male is closest.
Other recent publications
· Steven, C.R., J. Hill, B.S. Masters, and A.R. Place. 2005. Genetic markers in blue crabs (Callinectes sapidus) I: isolation and characterization of microsatellite markers. Journal of Experimental Marine Biology and Ecology. 319: 3-14. (PDF available)
· Johnson, L. S., L. E. Wimmers, B. G. Hicks, R. Molinaro, R. C. Milkie, B. S. Gallagher and B. S. Masters. 2005. Offspring sex vs. position in the laying sequence in Wyoming house wrens (Troglodytes aedon): a second look. Animal Behaviour. 70:1323-1329. (PDF available)
· Balenger, S.L., L.S. Johnson and B.S. Masters. 2009. Sexual selection in a socially monogamous bird: male color predicts paternity success in the mountain bluebird, Sialia currucoides. Behavioral Ecology and Sociobiology. 63:403-411. (PDF available)
· Balenger, S.L., L.S. Johnson, H.L. Mays, and B.S. Masters. 2009. Extra-pair paternity in the socially monogamous mountain bluebird (Sialia currucoides) and its effect on the potential for sexual selection. Journal of Avian Biology. 40:172-180. (PDF available)
Undergraduate Students:
Graduate Students: