High serum free fatty acids and low leptin levels: Plausible metabolic indicators of negative energy balance in early lactating Murrah buffaloes

Lactation is a highly demanding event in mammals, including buffaloes. It modulates the partitioning of nutrients, energy utilization, and food intake of the mother to meet her own and infant's energy needs. Failure to satisfy these energy needs leads to Negative Energy Balance (NEB). Currently, the only available indirect NEB indicator is Body Condition Score (BCS). However, direct dependency of the BCS on the peak depletion of body fat causes its inefficient use in a dairy farm. Thus, to establish objective NEB indicators in buffaloes, the serum levels of biochemical (serum β-hydroxybutyrate [BHBA] and free fatty acids [FFAs]), and endocrine (Growth Hormone [GH], insulin-like growth factor1 [IGF1], Insulin, and leptin) parameters were estimated in buffaloes. Our results revealed that serum FFA levels were significantly (p < 0.05) higher in high milk yielders (HMY) than low milk yielders (LMY) and heifers (H) during the 3rd and the 4th weeks of postpartum. The serum FFA levels were also significantly (p < 0.001) higher in the postpartum buffaloes with BCS < 3 in the field conditions. Further, serum leptin levels were significantly (p < 0.05) lower in HMY than LMY during the 3rd week of postpartum. However, the BHBA, GH, IGF1, and insulin levels were not significantly different between lactating buffaloes and H. These observations indicated that the NEB condition is probably restricted to the first month of early lactation in buffaloes. In conclusion, the simultaneous higher FFA and lower leptin levels could act as direct plausible metabolic indicators of NEB in buffaloes.     

Recording of DNA-binding events reveals the importance of a repurposed Candida albicans regulatory network for gut commensalism

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分子生态网络揭示冶金微生物对能源底物的响应

通过分析不同铁硫比的能源底物驯化下冶金微生物群落的演替过程,基于分子生态网络揭示冶金微生物对能源底物的响应特征。对富铁少硫、富硫少铁条件下不同驯化批次的微生物样本进行高通量测序,分析物种组成,比较冶金微生物群落的α多样性和β多样性,并构建分子生态网络,探究驯化过程微生物之间的相互作用关系。鉴定关键物种,分析冶金微生物群落对能源底物的响应。研究发现在基于不同能源底物驯化过程中,富铁少硫群落的优势物种为嗜酸氧化亚铁硫杆菌Acidithiobacillus ferrooxidans和铁氧化嗜酸硫杆菌A.ferriphilus;而富硫少铁群落经过3个批次的驯化,氧化硫硫杆菌A. thiooxidans占比高达90%。α、β多样性分析结果表明,富硫少铁能源底物驯化过程使冶金微生物群落多样性降低,且随着驯化批次的增加群落组成发生显著变化。分子生态网络分析显示关键物种均为低丰度稀有物种,富硫少铁条件下菌种间具有更紧密的互作共生关系,群落更加稳定。通过该驯化实验,明确了不同能源底物对冶金微生物群落的影响。采用富硫少铁能源底物驯化冶金微生物,使冶金微生物群落更加稳定,有助于优势物种高效发挥铁、硫氧化功能...     

拟南芥在盐胁迫环境下SOS转录调控网络的构建及分析

研究拟南芥在高浓度盐处理环境下的基因调控网络, 有助于了解其在盐胁迫环境下保持正常生长的防御机制。针对目前广泛研究的SOS (Salt Overly Sensitive)耐盐机制, 文章整合公共数据库中盐胁迫相关的拟南芥基因组表达谱芯片, 通过反向工程方法构建了拟南芥在盐胁迫状态下的SOS转录调控网络。所获得的调控网络包含70个盐胁迫相关且高度互作的互作基因, 其中27个转录因子为主要调控节点。进而根据SOS核心基因的表达特性, 所得调控网络内的不同表达模式得到了鉴别。     

黄河小浪底人工混交林生长季能量平衡特征

利用涡度相关系统和小气候梯度观测系统,对黄河小浪底人工混交林2012年生长季(5—9月)各能量通量进行了连续观测,分析了该生态系统能量平衡各项的变化特征,讨论了能量闭合状况。结果表明:潜热通量、感热通量和土壤热通量均与净辐射有类似的日变化特征。各项的绝对值大小表现为净辐射潜热通量感热通量土壤热通量。受日照时数的影响,5—9月能量平衡各项正值的日持续时间逐渐缩短。生长季,净辐射、感热通量和土壤热通量在6月份最大,最大值分别为418.5、231.4和12.5 MJ m-2month-1);潜热通量在7月份达到最大,最大值为320.8 MJ m-2month-1)。潜热通量、感热通量和土壤热通量占净辐射的比例分别在0.48—0.62、0.15—0.55、0.02—0.05之间。人工混交林生长季的能量分配主要以潜热通量和感热通量为主,且潜热通量为感热通量的2倍。波文比呈单峰曲线:6月最大,8月最小。黄河小浪底人工混交林生长季全天能量闭合度为79%。其中,白天闭合程度较高(81%),夜晚较低(41%)。本研究站点存在21%的能量不闭合。其原因可能与通量源区面积不匹配、忽略冠层热储存、湍流能的相位差等有关。     

Insights into the molecular regulatory network of pathomechanisms in osteochondroma

Osteochondroma is a benign autosomal dominant hereditary disease characterized by abnormal proliferation of cartilage in the long bone. It is divided into solitary osteochondroma and hereditary multiple exostoses (HMEs). The exostosin-1 (EXT-1) and exostosin-2 (EXT-2) gene mutations are well-defined molecular mechanisms in the pathogenesis of HME. EXT-1 and EXT-2 encode glycosyltransferases that are necessary for the synthesis of heparin sulfate. Accumulating evidence suggests that mutations in the EXT family induce changes in isolated hypogonadotropic hypogonadism-parathyroid hormone-related protein, bone morphogenetic protein, and fibroblast growth factor signaling pathways. Studies have also found that a large number of microRNAs (miRNAs) are abnormally expressed in osteochondroma tissues, and some of them also participate in several major signaling pathways. The regulation of miRNA expression could be another breakthrough in the treatment of osteochondroma. Although the pathogenesis of osteochondroma is very complicated, significant progress has been made in recent years. It is hoped that the pathogenesis of osteochondroma will be clearly understood and the most effective methods for the prevention and treatment of osteochondroma will be determined. This review provides an update on the recent progress in the interpretation of the underlying molecular mechanisms of osteochondroma.     

Evolutionary pattern of the regulatory network for flower development: Insights gained from a comparison of two Arabidopsis species

Abstract Previous studies on Arabidopsis thaliana and other model plants have indicated that the development of a flower is controlled by a regulatory network composed of genes and the interactions among them. Studies on the evolution of this network will therefore help understand the genetic basis that underlies flower evolution. In this study, by reviewing the most recent published work, we added 31 genes into the previously proposed regulatory network for flower development. Thus, the number of genes reached 60. We then compared the composition, structure, and evolutionary rate of these genes between A. thaliana and one of its allies, A. lyrata. We found that two genes (FLC and MAF2) show 1: 2 and 2: 2 relationships between the two species, suggesting that they have experienced independent, post‐speciation duplications. Of the remaining 58 genes, 35 (60.3%) have diverged in exon–intron structure and, consequently, code for proteins with different sequence features and functions. Molecular evolutionary analyses further revealed that, although most floral genes have evolved under strong purifying selection, some have evolved under relaxed or changed constraints, as evidenced by the elevation of nonsynonymous substitution rates and/or the presence of positively selected sites. Taken together, these results suggest that the regulatory network for flower development has evolved rather rapidly, with changes in the composition, structure, and functional constraint of genes, as well as the interactions among them, being the most important contributors.