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Current Lab Members

Katherine Ona

I completed my Master’s Degree in Biology at Portland State University, where I studied mechanisms by which actively dividing cells process different forms of DNA damage using the model organism E. coli (Pubmed links). After graduate school, I landed an opportunity to continue my research here at UNLV as the Robleto Lab technician/manager. When not hard at work in the lab, I enjoy cooking and hanging out with my dog, Charles.                 

Holly Martin

About Me


I am a third year graduate student.  I received my undergraduate degree in Biology from Morningside College in Sioux City, IA, where I also swam on the women’s swim team.  When I am not hard at work in the lab, I enjoy watching baseball and hxc two-stepping.



The focus of my work is to determine the role of transcription in stationary phase mutagenesis.   Previous work has shown that defects in DNA synthesis and repair systems contribute to the formation of adaptive mutations; however the role of transcription in the accumulation of mutations is still being examined.  One model hypothesizes that increased transcription will lead to an increase in the accumulation of mutations.  We test the transcription associated mutagenesis hypothesis by modulating the level of transcription of a defective leuC allele through the use of riboswitches, a mechanism of transcriptional control mediated by the interaction of the mRNA message and a small effector molecule. Our assays measure reversion to leucine prototrophy in stationary phase conditions.

Alessio Luinetti

About Me

My name is Alessio Luinetti and I just graduated from UNLV with a B.S. in Biology. I’m originally from Milan (Italy) but I’ve been living in Las Vegas for quite sometime. I will be starting Osteopathic School next academic year. When I am not hard at work in the lab, I enjoy playing soccer and using boxes.


Previous work in our lab has focused on adaptive mutations under conditions of stress caused by amino acid starvation. My work focuses on expanding this model to carbohydrate utilization in B. subtilis. We created the prototrophic strain YB007 to conduct stationary phase assays on glucose-free media containing alternative complex carbohydrate sources; this inhibits catabolite repression and allows for transcription of survival mode genes, such alpha-amylases. We also de-repressed the lacR repressor gene, which controls the cryptic lac Operon in subtilis.

I am now using the gram positive bacterium, B. subtilis, to investigate how different aspects of RNA transcription may lead to mutagenesis in non-dividing cells. More specifically, we are elucidating the role of transcription factors and transcription-induced secondary structures in stationay phase mutagenesis . I am also interested in the DNA repair mechanisms that prevent the accumulation of mutations during stationary phase that independent of RecA.

About me


Carmen Vallin—Effects of transcription-induced formation of DNA structures on adaptive mutagenesis

Mary Girard

Chad Hansen—Accumulation of mutations in genes that confer antibiotic resistance

Brandon Eisinger

Sharonda Strider  effects of transcription elongation factors on stationary phase  mutagenesis

About Me

Brandon Eisinger is currently an undergraduate senior majoring in pre-professional Biology at UNLV. He is finishing up his first year working in Dr. Robleto’s Microbial Genetics Laboratory and is also a Humanitarian Officer of Alpha Epsilon Delta. In his spare time he enjoys working out and going to rock concerts.


My current research is centered on the topic of stationary phase mutagenesis in the organism Bacillus subtilis. Bacteria only transcribe a subset of their genes that are necessary for growth and survival under specific environmental conditions while other DNA regions remain silent. Cells under conditions of starvation, or prolonged nonlethal selective pressures, accumulate mutations in these transcribed genes, including those transcribed as a result of environmental stress.


My research investigates the mutation rates for two different strains of Bacillus subtilis, a relA- mutant and the wild type YB955, and whether these strains accumulate mutations differently in genes that confer antibiotic resistance.



Former Lab Members

About Me

I grew up on the outskirts of Las Vegas, graduating from Boulder City High School, and have been attending UNLV since.  I have been working in Dr. Robleto’s lab for about a year and a half now.  I am also in the Honor’s College and will be graduating this May with a Bachelor’s of Science degree in Biology.  After graduation I plan to attend graduate school and pursue a degree in microbiology.  When not hard at work in lab, I spend my time chasing after my kids, watching Smosh.com, and feeding my newfound love of sushi.


We study the various genetic factors contributing to the mutagenic process known as stationary phase, or adaptive mutagenesis.  When cells in non-dividing conditions due to a given stressor, mutations randomly accumulate.  It is possible that these mutations may prove to be beneficial, conferring the ability to go back into replication mode.  Our overall goal is to better understand how these mutations occur in the cell.  My project’s specific goal is to determine the interaction between error-prone DNA polymerases and transcription elongation factors and their influence on rates of adaptive mutagenesis.