生物科学项目

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分会报告2A -口头报告

Climate change is an imminent threat to biodiversity, as evidenced by population declines in many 其中物种. In addition to long-term occupancy studies, an increasingly-popular monitoring method is non-invasively analyzing individual stress via fecal glucocorticoid metabolites (GCM). The American pika (Ochotona princeps) is a small lagomorph that is sensitive to rising temperatures and has experienced declines in parts of its range. 然而，有一个独特的种群存在 in the La Sal Mountains of southern Utah; this population is predicted to be vulnerable because of its 孤立的自然和南纬. To determine relative stress levels among pikas in this unique population, we collected pika scat along elevational transects during summer 2019. 然后我们使用了 information theoretic framework (AICc) to test competing hypotheses related to the effects of climate, biogeography, and habitat area on pika physiological condition (GCM) along elevational gradients. Elevation was the single strongest predictor of fecal GCM, with higher stress at higher elevation. Although seemingly counterintuitive, 2018-2019 saw abnormally high snowpack and avalanche activity, which reduced food availability in the spring and shortened the haying season at high elevation. 这些 results advance the investigation of how climate-sensitive species respond to climate change and its 不可预测性.

Members of the soil-dwelling bacterial genus Streptomyces are primarily known for their production 次生代谢物. 这些 filamentous, spore-producing bacteria are widely distributed in soil 并在动植物中引起各种疾病. 盘形骨虫是一种生活在土壤中的变形虫 energy and nutrients by consuming bacteria, but potential interactions with streptomycetes have not 被广泛研究过. We have isolated streptomycetes and dictyostelid strains from a variety 当地的土壤，并开始识别它们. 至少有一个盘状骨鞘生长时，孢子从 Streptomyces strains with which they were co-isolated are provided as the sole energy source, and we 继续评估潜在的相互作用. 这些 experiments are important for establishing a better understanding of predator-prey interactions within the soil, 为了理解变形虫的生物学, and perhaps for understanding virulence in Streptomyces strains that can cause disease.

Photuris fireflies exhibit an evolutionarily novel photic organ for which the underlying genetic regulation remains unknown. The photic organ is a posterior-ventral structure that serves to catalyze and reflect luminescent reactions. An important feature of the photic organ is that it is overlain by a depigmented cuticle that facilitates luminesce transmission during courtship rituals. However, the genes responsible for the depigmentation remain unidentified. In Drosophila melanogaster, the genes black and ebony are known to repress cuticular pigmentation. We hypothesized that these functions are conserved in Photuris fireflies and that one or both genes have been recruited in the depigmentation of the photic organ’s cuticle. We used RNA interference (RNAi) to intentionally inhibit expression of each target during pupal development. Microscopic examination of the adult RNAi individuals suggests that ebony is involved in the depigmentation of the cuticle surrounding the photic organ of female fireflies, while black is suspected to be involved in pigmentation patterning of the ventral thorax and appendages. 这些 results suggest that photic organ pigment repression is complex and sex-specific in Photuris fireflies.

议题2B -海报展示

Dictyostelium discoideum is a soil dwelling amoeba that is commonly studied due to its unique life cycle in which starving amoeba aggregate to form multicellular reproductive structures, 称为子实体. Although the life cycle has been studied extensively in the laboratory, less is known about the biology of these amoebae in soil. I have assessed whether Dictyostelium amoebae consume Streptomyces bacteria to understand the role of these social amoeba in soil. 链菌是产生丝状孢子的细菌, 几乎存在于所有土壤中, that are known for their production 次生代谢物. 这些 metabolites have antibacterial and antifungal activities. My experiments show that Dictyostelium amoebae are capable of growing when spores from one of several Streptomyces species are supplied as the only food source. 所有测试的菌株都支持变形虫的生长. 这些 experiments suggest that Streptomyces spores may be a major food source of amoebae in soil and that the amoebae may be a good model to understand microbiological predator-prey relationships in soil.

There has been a global decline in amphibian populations and one major contributor is the fungus Batrachochytrium dendrobatidis (Bd), 壶菌病的病因是什么. This pathogen infects the skin of amphibians where it can inhibit electrolyte and gas exchange, 最终导致死亡. There are multiple methods of disease management including laboratory treatments and fungicide applications. However, many of these strategies are either ineffective or unsafe. Recent research has shown that the bacteria Bacillus thuringiensis, 在农业生物农药中发现, 产生抗真菌的挥发性有机化合物. If Bd growth is inhibited by these VOCs, then there should be reduced Bd growth when B. 苏云金和Bd相邻生长. Bd与B并排镀. thuringiensis in a divided petri dish and incubated for 14 days. Photos of each plate were analyzed using Image J to assess percentage of Bd cover. 结果表明B. thuringiensis VOCs significantly inhibited growth of Bd when compared to control plates. This suggests that a widely used biopesticide may be helpful in disease prevention for amphibians with overlapping habitat. This research is an important step towards developing effective disease management strategies for amphibians using common agricultural products.

根据全身评分系统, decomposition of human remains can be broken up into four stages: fresh, 早期的分解, 高级分解和骨骼化. The timing and characteristics of these stages vary in different environments (i.e. 湿与. 干旱的环境). At pp电子极速糖果’s Forensic Investigation Research Station (FIRS) the decomposition of human remains is observed with the goal of understanding how the process occurs in an arid, 高原沙漠环境. The aim of this study was to identify different fungi growing on human remains at FIRS. Tissue samples were taken from skin and bone and plated for continued growth in culture. Five different fungal species were identified based on morphological characteristics and grown in pure culture. DNA隔离, amplification and sequencing analyses were used to confirm the identity of each fungus based on their genetic sequences. 通过确认每种真菌的身份, we hope to conduct further research into the role of fungi in the different stages of decomposition, as well as the differences in fungal growth in different environments. Understanding the role of fungi in decomposition can aid in forensic investigations and determination of the post mortem interval in different crime scene environments.

Batrachochytrium dendrobatidis (Bd) is a fungal pathogen that has led to declines in amphibian populations worldwide. Some amphibians are protected from Bd infection by bacteria that they acquire from their environments. Bacillus thuringiensis (Bt) is a common soil bacteria that makes antifungal and antibacterial metabolites. We hypothesized that the presence of these metabolites in the liquid culture would inhibit the growth of Bd. Secondary metabolites were isolated from two Bt subspecies and tested against the Bd fungus in vitro. The secondary metabolites were extracted from broth cultures of Bt and used in a spectrophotometric growth assay against Bd for one week. It was found that when the metabolites were added to the liquid culture of Bd, 真菌比对照组生长得更好. The mechanisms by which the increased fungal growth is caused are unknown, but a possible explanation may lie in the signaling capabilities of Bd. Perhaps the fungus is capable of sensing the secondary metabolites and activating transcription factors thus, 促进细胞生长. This effect has been observed in other fungal studies utilizing secondary metabolites. Future studies may involve Bd signaling competency for both competition and growth factors.