Matthew J Greenwold

• PhD
• Professor (Assistant) at The University of Texas at Tyler

Traditional methods of forage identification are impractical to use with non-leafcutting fungus gardening ants, making diet-related ecological and life history questions difficult to study. In an attempt to address this limitation, we utilized dietary DNA metabarcoding as a method for directly identifying foraged substrate from the ant’s fungus gar...

Freshwater mussels are filter feeders that play an integral role in keeping our water systems healthy. Filter feeding influences the entire ecosystem through the transfer of energy, cycling of nutrients, and purification of water. Freshwater mussels form multispecies assemblages which may lead to food resource competition among species. This study...

As photosynthetic producers, phytoplankton form the foundation of aquatic food webs. Understanding the relationships among photosynthetic traits in phytoplankton is essential to revealing how diversification of these traits allows phytoplankton to harvest energy from different light environments. We investigated whether the diversification of 15 sp...

Advances in our understanding of symbiotic stability have demonstrated that microorganisms are key to understanding the homeostasis of obligate symbioses. Fungus-gardening ants are excellent model systems for exploring how microorganisms may be involved in symbiotic homeostasis as the host and symbionts are macroscopic and can be easily experimenta...

Advances in our understanding of symbiotic stability have demonstrated that microorganisms are key to understanding the homeostasis of obligate symbioses. Fungus-gardening ants are excellent model systems for exploring how microorganisms may be involved in symbiotic homeostasis as the host and symbionts are macroscopic and can be easily experimenta...

Cryptophytes are single celled protists found in all aquatic environments. They are composed of a heterotrophic genus, Goniomonas, and a largely autotrophic group comprising many genera. Cryptophytes evolved through secondary endosymbiosis between a host eukaryotic heterotroph and a symbiont red alga. This merger resulted in a four-genome system th...

Crayfish are often thought of as a meal with little regard to the roles they play in the environment. Crayfish are a critical group of organisms that serve as an intermediate for aquatic and terrestrial food web networks. Less commonly known, however, is that different species of crayfish that occupy different ecological niches can form hybrids. Th...

As photosynthetic producers, phytoplankton form the foundation of aquatic food webs. Understanding the relationships among photosynthetic traits in phytoplankton is essential to revealing how diversification of these traits allow phytoplankton to harvest energy from different light environments. We investigated whether the diversification of 15 spe...

Freshwater mussels are the most threatened fauna of North America. They provide millions of dollars in ecosystem services each year through water filtration. Despite their scarcity, a dozen or more species can be found in a single mussel bed in the Sabine River. Understanding these underappreciated bivalves, particularly in respect to resource...

The fungus gardening-ant system is considered a complex, multi-tiered symbiosis, as it is composed of ants, their fungus, and microorganisms associated with either ants or fungus. We examine the bacterial microbiome of Trachymyrmex septentrionalis and Mycetomoellerius turrifex ants and their symbiotic fungus gardens, using 16S rRNA Illumina sequenc...

The fungus gardening-ant system is considered a complex, multi-tiered symbiosis, as it is composed of ants, their fungus, and microorganisms associated with either ants or fungus. We examine the bacterial microbiome of Trachymyrmex septentrionalis and Mycetomoellerius turrifex ants and their symbiotic fungus gardens, using 16S rRNA Illumina sequenc...

Over the past few decades, large-scale phylogenetic analyses of fungus-gardening ants and their symbiotic fungi have depicted strong concordance among major clades of ants and their symbiotic fungi, yet within clades, fungus sharing is widespread among unrelated ant lineages. Sharing has been explained using a diffuse coevolution model within major...

Over the past few decades, large-scale phylogenetic analyses of fungus-gardening ants and their symbiotic fungi have depicted strong concordance among major clades of ants and their symbiotic fungi, yet within clades, fungus sharing is somewhat widespread among unrelated ant lineages. These symbioses are thought to be explained by a diffuse coevolu...

The transition of amniotes to a fully terrestrial lifestyle involved the adaptation of major molecular innovations to the epidermis, often in the form of epidermal appendages such as hair, scales and feathers. Feathers are diverse epidermal structures of birds, and their evolution has played a key role in the expansion of avian species to a wide ra...

Evolutionary biologists have long sought to identify phenotypic traits whose evolution enhances an organism's performance in its environment. Diversification of traits related to resource acquisition can occur owing to spatial or temporal resource heterogeneity. We examined the ability to capture light in the Cryptophyta, a phylum of single-celled...

The evolution of a mechanically-resilient epidermis was a key adaptation in the transition of amniotes to a fully terrestrial lifestyle. Skin appendages usually form via a specialized type of programmed cell death (PCD) known as cornification which is characterized by the formation of an insoluble cornified envelope (CE). Many of the substrates of...

Phenotypic traits associated with light capture and phylogenetic relationships were characterized in 34 strains of diversely pigmented marine and freshwater cryptophytes. Nuclear SSU and partial LSU rDNA sequence data from 33 of these strains plus an additional 66 strains produced a concatenated rooted maximum likelihood tree that classified the st...

Improved Biological Tissue Preparation Procedure for Scanning Electron Microscopic Imaging - Volume 24 Supplement - Habeeb Alsudani, Soumitra Ghoshroy, Joseph Quattro, Matthew Greenwold, Roger Sawyer

Gene co-expression network analysis has been a research method widely used in systematically exploring gene function and interaction. Using the Weighted Gene Co-expression Network Analysis (WGCNA) approach to construct a gene co-expression network using data from a customized 44K microarray transcriptome of chicken epidermal embryogenesis, we have...

Daphnia pulex has the largest known family of opsins, genes critical for photoreception and vision in animals. This diversity may be functionally redundant, arising from recent processes, or ancient duplications may have been preserved due to distinct functions and independent contributions to fitness. We analyzed opsins in D. pulex and its distant...

MicroRNAs (miRNAs) are small non-coding RNAs that regulate gene expression at the post-transcriptional level. Previous studies have shown that miRNA regulation contributes to a diverse set of processes including cellular differentiation and morphogenesis which leads to the creation of different cell types in multicellular organisms and is thus key...

Birds are the most species-rich class of tetrapod vertebrates and have wide relevance across many research fields. We explored bird macroevolution using full genomes from 48 avian species representing all major extant clades. The avian genome is principally characterized by its constrained size, which predominantly arose because of lineage-specific...

Vertebrate skin appendages are constructed of keratins produced by multigene families. Alpha (α) keratins are found in all vertebrates, while beta (β) keratins are found exclusively in reptiles and birds. We have studied the molecular evolution of these gene families in the genomes of 48 phylogenetically diverse birds and their expression in the sc...

Birds are the most species-rich class of tetrapod vertebrates and have wide relevance across many research fields. We explored bird macroevolution using full genomes from 48 avian species representing all major extant clades. The avian genome is principally characterized by its constrained size, which predominantly arose because of lineage-specific...

Birds are the most species-rich class of tetrapod vertebrates and have wide relevance across many research fields. We explored bird macroevolution using full genomes from 48 avian species representing all major extant clades. The avian genome is principally characterized by its constrained size, which predominantly arose because of lineage-specific...

Penguins are flightless aquatic birds widely distributed in the Southern Hemisphere. The distinctive morphological and physiological features of penguins allow them to live an aquatic life, and some of them have successfully adapted to the hostile environments in Antarctica. To study the phylogenetic and population history of penguins and the molec...

Prior to Spring Semester 2011, the University of South Carolina Biological Sciences curriculum offered only a face‐to‐face histology course where students were required to attend lectures and labs utilizing the microscope. Laboratory space and equipment limited enrollment in the face‐to‐face class which never exceeded 50 consisting mainly of pre‐me...

The archosauria consist of two living groups, crocodilians, and birds. Here we compare the structure, expression, and phylogeny of the beta (β)-keratins in two crocodilian genomes and two avian genomes to gain a better understanding of the evolutionary origin of the feather β-keratins. Unlike squamates such as the green anole with 40 β-keratins in...

The International Crocodilian Genomes Working Group (ICGWG) will sequence and assemble the American alligator (Alligator mississippiensis), saltwater crocodile (Crocodylus porosus) and Indian gharial (Gavialis gangeticus) genomes. The status of these projects and our planned analyses are described.

Feathers of today's birds are constructed of beta (β)-keratins, structural proteins of the epidermis that are found solely in reptiles and birds. Discoveries of "feathered dinosaurs" continue to stimulate interest in the evolutionary origin of feathers, but few studies have attempted to link the molecular evolution of their major structural protein...

Expressed Sequence Tag BLAST results. List of all β-keratin sequences in the genomes of G. gallus and T. guttata that had at least an E-value score of 1e-160 and 1e-150, respectably, for an expressed sequence tag (EST). EST database was downloaded via NCBI for each species. The GI number for each EST, region of the EST matching the coding region of...

Two-dimensional Gels of β-keratin Expression in Chick Epidermal Appendages. Reprint of Figure 2 in Shames et al [19]. Two-dimensional gels of protein extracted from 19-20 day embryonic chick (A) scutate scale epidermis, (B) cornified beak, (C) egg tooth, (D) periderm, and (E) claw. The acidic (Ac) and basic (Ba) ends of the gel and the molecular we...

Tree Reconstruction of all β-keratin genes found in the Gallus gallus and Taeniopygia guttata Genomes. Neighbor-Joining tree reconstruction of the 219 β-keratin nucleotide sequences from both avian genomes and the three nile crocodile sequences as the outgroup. The subfamilies are colored with the following scheme: GGA25_Keratinocyte = red, scale β...

Annotation of β-keratins resulting from BLAST Searches of the Gallus gallus and Taeniopygia guttata Genomes. List of all sequences used in this study that resulted from a BLAST search of the G. gallus and T. guttata genomes [7,8]. Annotation of each sequence used in this study, its position on its respective chromosome, and strand orientation is in...

PAML Analysis of all Feather β-keratin Loci that Resulted in Positively Selected Sites: The six models are listed in the first column with a brief description, and the values obtained from each analysis are listed in their respective rows. The dN/dS ratios are the average of the sum of all branches. All positively selected sites above 95% are liste...

Tree Reconstruction of all β-keratin genes found in the Gallus gallus and Taeniopygia guttata Genomes. Maximum Likelihood tree reconstruction of the 219 β-keratin nucleotide sequences from both avian genomes and the three nile crocodile sequences as the outgroup. The subfamilies are colored with the following scheme: GGA25_Keratinocyte = red, scale...

The epidermal appendages of reptiles and birds are constructed of beta (beta) keratins. The molecular phylogeny of these keratins is important to understanding the evolutionary origin of these appendages, especially feathers. Knowing that the crocodilian beta-keratin genes are closely related to those of birds, the published genomes of the chicken...