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Monica A Kehoe

Publications and source records attributed to Monica A Kehoe.

2 recordsLinked to original sources
bioRxiv2016

Genetic Diversity, Population Structure and Species Delimitation of Trialeurodes vaporariorum (Greenhouse whitefly)

Genetic diversity within Trialeurodes vaporariorum (Westwood, 1856) remains largely unexplored, particularly within regions of Sub-Saharan Africa. In this study, T. vaporariorum samples were obtained from three locations in Kenya: Katumani, Kiambu and Kajiado counties. DNA extraction, PCR and Sanger sequencing were carried out on ~750 bp fragment of the mitochondria cytochrome c oxidase I (COI) gene from individual whiteflies. In addition, global populations were assessed and 19 haplotypes were identified, with three main haplotypes (Hp_19, Hp_10, Hp_011) circulating within Kenya. Measures of genetic diversity among T. vaporariorum populations resulted in haplotype diversity of 0.411, nucleotide diversity 0.00096, and Tajimas D -0. 30315, (P>0.10). Analysis of population structure across global sequences using Structurama indicated one population globally, with posterior probability of 0.72. Bayesian and maximum likelihood phylogenetic analysis gave support for two clades (Clade I = an admixed global population and Clade II = subset of Kenyan and 1 Greek sequence). Species delimitation between the two clades was assessed by four parameters; posterior probability, Kimuras two parameter (K2P), Rodrigos P (Randomly distinct) and Rosenbergs reciprocal monophyly (P(AB). The two clades within the phylogenetic tree showed evidence of distinctness based on; Kimura two parameters (K2P) (p = -1.21E-01), Rodrigos P (RD) (p =0.05) and Rosenbergs P(AB) (p = 2.3E -13). Overall, low genetic diversity within the Kenyan samples is a likely indicator of recent population expansion and colonization with this region and plausible signs of species complex formation in Sub-Saharan Africa.

Evolutionary Biology↗
bioRxiv2016

Characterization by Next Generation Sequencing Reveals the Molecular Mechanisms Driving the Faster Evolutionary rate of Cassava brown streak virus Compared with Ugandan cassava brown streak virus

Cassava is a major staple food for about 800 million people in the tropics and subGtropical regions of the world. Production of cassava is significantly hampered by cassava brown streak disease (CBSD), which is caused by Cassava brown streak virus (CBSV) and Ugandan cassava brown streak virus (UCBSV). The disease is suppressing cassava yields in eastern Africa at an alarming rate. Previous studies have documented that CBSV is more devastating than UCBSV because it more readily infects both susceptible and tolerant cassava cultivars, resulting in greater yield losses. Using whole genome sequences from NGS data, we produced the first coalescentGbased species tree estimate for CBSV and UCBSV. This species framework led to the finding that CBSV has a faster rate of evolution when compared with UCBSV. Furthermore, we have discovered that in CBSV, nonsynonymous substitutions are more predominant than synonymous substitution and occur across the entire genome. All comparative analyses between CBSV and UCBSV presented here suggest that CBSV may be outsmarting the cassava immune system, thus making it more devastating and harder to control.

Evolutionary Biology↗