Factors Affecting the Level of Triglycerides in Black-legged Kittiwake Seabird Chicks (Rissa tridactyla)

Plasma metabolites such as glucose, cholesterol, and triglycerides, may act as health indicators in birds. Many factors can influence metabolite levels such as sex, age, diet, body mass, and glucocorticoid-induced energy mobilization. However, to date, there is a lack of consistency in the patterns of metabolites in early chick development stages. Our study will provide insight into how biological processes including nutritional status, chick rank, age, and sex affect triglyceride levels in black-legged kittiwake chicks. Our experiments were conducted in Middleton Island, Alaska, with known age and rank chicks. Chicks came from two types of nests for nutritional status: fed (experimental treatment) and unfed (control). Whereas the fed nests were supplied with unlimited fish, the unfed nests only had food from parental foraging at sea. The chicks were genetically sexed. We hypothesize that the level of triglycerides differs based on sex, chick ranking, and food intake.

Microtus ochrogaster Exhibit Increased Anxiety Behaviors to a Stressor in the Absence of a Partner
Social isolation has been shown to be detrimental to mental and physical well-being. Its influence has been observed in impaired neuroendocrine, cardiovascular, and immune system functioning, and has been implicated in anxiety and depression, as well as in lowered self-esteem and suicidal ideation. Conversely, positive social experiences and meaningful social connections have been implicated in improved mental and physical health, increased immune response, and an increase in lifespan. The prairie vole (M. ochrogaster) has proven to be useful in the laboratory setting for their ability to demonstrate selectivity in their relationships, and, thus, were ideal for the purposes of this study.
The objective of this project was to examine whether social support during exposure to an ecologically significant stressor is capable of reducing the negative consequences of the stressor itself. For the stressor, we utilized an ecologically relevant chemical called TMT, which is a component of fox feces. We explore this topic in the hopes of illuminating the importance of social connection in the face of experiences that elicit a stress response.

Solanum acanthophisum: a new dioecious bush tomato species from the Australian Monsoon Tropics
Estimates suggest that over 70% of the Australian flora and fauna has yet to be scientifically described. Numerous new plant species are still being described each year from across the continent. Here, we investigate a potential new species represented by just a few herbarium collections made in the remote Deaf Adder Gorge of Kakadu National Park, a biodiversity hotspot and UNESCO World Heritage Site. The new taxon was previously suggested as a possible localized variant of the functionally dioecious Kakadu endemic Solanum asymmetriphyllum and close relative of its sister species S. sejunctum. Using seeds removed from a herbarium sheet, a single ex situ plant was grown and used to assess more than 30 morphological characters to document the differences among S. asymmetriphyllum, S. sejunctum, and the putative new species. Morphometric analyses provide evidence that the three taxa are distinct from one another and support the segregation of the Deaf Adder Gorge variant as Solanum acanthophisum sp. nov. The specific epithet, “acanthophisum” is derived from the generic name of the sympatric death/deaf adder snake, Acanthophis praelongus. Solanum acanthophisum is now one of three recognized Solanum species occurring in Kakadu that exhibit functional dioecy, a sexual system in which morphologically bisexual flowers produce non-functional inaperturate pollen.

Segregation of the Univalent X Chromosome in the Two-striped Planthopper Acanalonia bivittata

Correct segregation in meiosis I depends on homologous chromosomes pairing to form bivalents. To achieve a successful reduction in ploidy, bivalents align on the metaphase plate and then homologues segregate during anaphase I. While bivalent formation is generally required for correct segregation in meiosis I, many organisms pose an exception to this requirement. Our objective was to study one such exception, the two-striped planthopper Acanalonia bivittata (Hemiptera, Auchenorrhyncha), which has a univalent X chromosome. A. bivittata were collected and their identification was confirmed through DNA barcoding. Chromosome number was found to be consistent with previously published karyotypes for the species. To observe the behavior of unpaired chromosomes in male primary spermatocytes, live-cell and confocal imaging of stained cells was conducted. The univalent X chromosomes were found to be characterized by independent and delayed segregation that occurred after autosomal segregation during early anaphase I. Delayed segregation of the univalent chromosome was associated with the loss of microtubule connections to one spindle pole, leaving the chromosome aligned on the metaphase plate, often in a position outside the main spindle body. This study characterized the behavior of an unpaired chromosome in an alteration to the traditional meiotic program. This work has translational implications in organisms in which a chromosomal pairing partner is lost, such as the diminution and potential loss of a Y chromosome in mammals.

Segregation of the Univalent X Chromosome in the Two-striped Planthopper Acanalonia bivittata

Correct segregation in meiosis I depends on homologous chromosomes pairing to form bivalents. To achieve a successful reduction in ploidy, bivalents align on the metaphase plate and then homologues segregate during anaphase I. While bivalent formation is generally required for correct segregation in meiosis I, many organisms pose an exception to this requirement. Our objective was to study one such exception, the two-striped planthopper Acanalonia bivittata (Hemiptera, Auchenorrhyncha), which has a univalent X chromosome. A. bivittata were collected and their identification was confirmed through DNA barcoding. Chromosome number was found to be consistent with previously published karyotypes for the species. To observe the behavior of unpaired chromosomes in male primary spermatocytes, live-cell and confocal imaging of stained cells was conducted. The univalent X chromosomes were found to be characterized by independent and delayed segregation that occurred after autosomal segregation during early anaphase I. Delayed segregation of the univalent chromosome was associated with the loss of microtubule connections to one spindle pole, leaving the chromosome aligned on the metaphase plate, often in a position outside the main spindle body. This study characterized the behavior of an unpaired chromosome in an alteration to the traditional meiotic program. This work has translational implications in organisms in which a chromosomal pairing partner is lost, such as the diminution and potential loss of a Y chromosome in mammals.