Doctor of Philosophy (Ph.D.)

Biology
Johns Hopkins University
2007

Bachelor of Science (B.S.)

Biology and Environmental Studies
George Washington University
2001

Genetics, Developmental Biology, Molecular Biology

Genetics (BIOL200)

Developmental Biology (BIOL413 / 713)

2017 Exemplary Syllabus Award Winner CETLA, Howard University

2016 Advanced Summer Faculty Research Fellowship, Howard University

2016 Exemplary Syllabus Award Winner CETLA, Howard University

Society for Developmental Biology Teaching Faculty Award

2014-15 ASCB/NSF Faculty Research and Education Developmental (FRED) Award

Comparison of N- and C-terminally endogenously GFP-tagged WEE-1.3 strains in C. elegans

Comparison of N- and C-terminally endogenously GFP-tagged WEE-1.3 strains in C. elegans 

We have generated a WEE-1.3 strain in C. elegans where we have endogenously tagged the C-terminus with GFP. In this publication we demonstrate that this new strain exhibits the same expression localization pattern as the WEE-1.3 antibody and N-terminally endogenously GFP-tagged WEE-1.3 strain that have been previously published. We also show for the first time that endogenously tagging WEE-1.3 at either termini does not affect the reproductive function of the worms.

The Caenorhabditis elegans proteasome

The Caenorhabditis elegans proteasome subunit RPN-12 is required for hermaphrodite germline sex determination and oocyte quality

The proteasome is a multi-subunit complex and a major proteolytic machinery in cells. Most subunits are essential for proteasome function, and depletion of individual subunits normally results in lethality. RPN-12/Rpn12/PSMD8 is a lid subunit of the 19S regulatory particle (RP) of the 26S proteasome. Studies in Caenorhabditis elegans demonstrated that RNAi depletion of RPN-12 does not result in lethality. RPN-12 has not been well studied in higher eukaryotes. In this study, we investigate the biological significance of RPN-12 in C. elegans. We found that the null mutant rpn-12(av93) did not cause major impairment of the proteolytic activity of the proteasome.

Loss of proteasome subunit RPN-12

 Loss of proteasome subunit RPN-12 causes an increased mean lifespan at a higher temperature in C. elegans

Our data suggests that RPN-12 is not essential for viability and lifespan of C. elegans under normal conditions (20ºC), but that absence of RPN-12 can result in a significant increase in mean lifespan under heat stress (25ºC).

Facilitating Growth through Frustration

Facilitating Growth through Frustration: Using Genomics Research in a Course-Based Undergraduate Research Experience

A hallmark of the research experience is encountering difficulty and working through those challenges to achieve success. This ability is essential to being a successful scientist, but replicating such challenges in a teaching setting can be difficult. The Genomics Education Partnership (GEP) is a consortium of faculty who engage their students in a genomics Course-Based Undergraduate Research Experience (CURE). Students participate in genome annotation, generating gene models using multiple lines of experience is continuous and recursive, frequently beginning with frustration but eventually leading to success as they come up with defendable gene models.

Mini-course based undergraduate research experience

Mini-course based undergraduate research experience: Impact on student understanding of STEM research and interest in STEM programs

Undergraduate research experiences (UREs) increase interest in STEM (science, technology, engineering, and mathematics) research and careers. UREs are utilized as recruitment tools for advanced degree programs and often target underrepresented minorities (URMs). However, UREs accommodate a limited number of students. Course-based UREs (CUREs) have the same benefits as UREs and reach more students, but traditionally cannot be used for recruitment. Here we describe and assess a 1-week “miniCURE” for the perceived value of its components and ability to meet course learning objectives, provide similar research benefits, and serve as a URM recruitment tool.

New Role for an Old Protein

New Role for an Old Protein: An Educational Primer for Use with “The Identification of a Novel Mutant Allele of topoisomerase II in Caenorhabditis elegans Reveals a Unique Role in Chromosome Segregation During Spermatogenesis

This Primer article is designed to provide essential background information on C. elegans spermatogenesis and the relevant scientific techniques that will assist students and instructors in their understanding and discussion of the related article.

The GEP: Crowd-Sourcing Big Data Analysis with Undergraduates

The GEP: Crowd-Sourcing Big Data Analysis with Undergraduates

The era of ‘big data’ is also the era of abundant data, creating new opportunities for student–scientist research partnerships. By coordinating undergraduate efforts, the Genomics Education Partnership produces high-quality annotated data sets and analyses that could not be generated otherwise, leading to scientific publications while providing many students with research experience.

An RNAi-based suppressor screen identifies interactors of the Myt1 ortholog of Caenorhabditis elegans

An RNAi-based suppressor screen identifies interactors of the Myt1 ortholog of Caenorhabditis elegans

This study sought to further define the precocious maturation phenotype and to identify novel interactors with WEE-1.3. We found that WEE-1.3 is expressed throughout the germline and in developing embryos in a perinuclear pattern, and demonstrated that oocytes in WEE-1.3-depleted germlines have begun to transcribe embryonic genes and exhibit inappropriate expression of proteins normally restricted to fertilized eggs.

Novel functions for the RNA-binding protein ETR-1 in Caenorhabditis elegans reproduction

Novel functions for the RNA-binding protein ETR-1 in Caenorhabditis elegans reproduction

 In this study, we show that ETR-1 is expressed in the hermaphrodite somatic gonad and germ line, and that reduction of ETR-1 via RNA interference (RNAi) results in reduced hermaphrodite fecundity. Detailed characterization of this fertility defect indicates that ETR-1 is required in both the somatic tissue and the germ line to ensure wild-type reproductive levels.

emb-1 encodes the APC16 subunit of the Caenorhabditis elegans Anaphase-Promoting Complex

emb-1 encodes the APC16 subunit of the Caenorhabditis elegans Anaphase-Promoting Complex

In the nematode Caenorhabditis elegans, temperature-sensitive mutants of emb-1 arrest as one-cell embryos in metaphase of meiosis I in a manner that is indistinguishable from embryos that have been depleted of known subunits of the anaphase-promoting complex or cyclosome (APC/C). Here we show that the emb-1 phenotype is enhanced in double mutant combinations with known APC/C subunits and suppressed in double mutant combinations with known APC/C suppressors. In addition to its meiotic function, emb-1 is required for mitotic proliferation of the germline. These studies reveal that emb-1 encodes K10D2.4, a homolog of the small, recently discovered APC/C subunit, APC16.

The SF-1-like nuclear hormone receptor Hr39

The SF-1-like nuclear hormone receptor Hr39 regulated Drosophila female reproductive tract development and function

The vertebrate nuclear hormone receptor steroidogenic factor 1 (SF1; NR5A1)controls reproductive development and regulates the transcription of steroid-modifying cytochrome P450 genes. We find that the SF1-related Drosophila nuclear hormone receptor HR39 is also essential for sexual development. In Hr39 mutant females, the sperm-storing spermathecae and glandular parovaria are absent or defective, causing sterility. Our results indicate that spermathecae and parovaria secrete reproductive tract proteins required for sperm maturation and function, like the mammalian epididymis and female reproductive tract.