布鲁菌进化和分类学研究进展

布鲁菌属革兰氏阴性兼性胞内寄生菌,能感染多种宿主动物和人。该属可分为6个典型种,包括羊种、牛种、猪种、沙林鼠种、绵羊附睾种以及犬种布鲁菌等。此分类是基于其致病性以及宿主偏好性的差异划分。尽管6个种通过传统表型试验能区分,但布鲁菌种内采用DNA-DNA杂交证明DNA同源性高度一致（相似性大于90%）。因此有人提议布鲁菌由单一种组成,即布鲁菌属中只有羊种布鲁菌,其他种都是羊种菌的生物亚型之一。然而基于其他分子技术的基因分型表明其DNA多态性表现明显,说明目前对这个种的分型还是比较准确。而最近分离的海洋种布鲁氏菌分离株（鳍型和鲸型）采用传统分型标准和一些特异的分子标记也证明这种分型比较正确。本文对目前布鲁菌种属进化和分类学进行综述,希望对研究其进化和分类有所帮助。     

蒺藜苜蓿LEA基因家族全基因组分析

胚胎发育晚期丰富蛋白(LEA)是一类在种子胚胎发育后期特异表达并受发育阶段及脱水信号调节的脱水保护蛋白,在响应植物干旱、低温、高盐等逆境胁迫中具有重要功能。本研究利用生物信息学手段,在全基因组水平对蒺藜苜蓿(Medicago truncatula)LEA基因家族进行分析,并对其进化、基因结构、进化压力、染色体定位及基因表达模式进行了系统分析。本研究共筛选出23个蒺藜苜蓿LEA家族基因,可分为8个亚家族。基因定位结果表明,23个蒺藜苜蓿LEA基因分布于除6号染色体外的其他7条染色体上,但分布不均匀;家族成员外显子数目都不超过两个,结构简单。不同组织表达谱分析结果显示,LEA家族基因具有不同的组织表达模式,并受干旱逆境胁迫调控。本研究结果可为蒺藜苜蓿LEA基因家族的功能分析奠定基础。     

Sequence diversity and molecular evolutionary rates between buffalo and cattle

Identification of genes of importance regarding production traits in buffalo is impaired by a paucity of genomic resources. Choice to fill this gap is to exploit data available for cow. The cross‐species application of comparative genomics tools is potential gear to investigate the buffalo genome. However, this is dependent on nucleotide sequences similarity. In this study, gene diversity between buffalo and cattle was determined using 86 gene orthologues. There was approximately 3% difference in all genes in terms of nucleotide diversity and 0.267 ± 0.134 in amino acids, indicating the possibility for successfully using cross‐species strategies for genomic studies. There were significantly higher non‐synonymous substitutions both in cattle and buffalo; however, there was similar difference in terms of dN– dS (4.414 versus 4.745) in buffalo and cattle, respectively. Higher rate of non‐synonymous substitutions at similar level in buffalo and cattle indicated a similar positive selection pressure. Results for relative rate test were assessed with the chi‐squared test. There was no significance difference on unique mutations between cattle and buffalo lineages at synonymous sites. However, there was a significance difference on unique mutations for non‐synonymous sites, indicating ongoing mutagenic process that generates substitutional mutation at approximately the same rate at silent sites. Moreover, despite of common ancestry, our results indicate a different divergent time among genes of cattle and buffalo. This is the first demonstration that variable rates of molecular evolution may be present within the family Bovidae.     

Mitogenome revealed multiple postdomestication genetic mixtures of West African sheep

Notable diversity observed within African ovine breeds makes them of great interests, but limited studies on genetic origins and domestications remain poorly understood. Here, we investigate the evolutionary status of West African native breeds, Djallonke and Sahelian sheep using mitogenome sequencing. Compared with other ovine mitogenome sequences, West African sheep were revealed a Eurasian origin, and the initially tamed sheep breeds in West Africa have been genetically mixed with each other and mixed with European breeds. Worldwide domestic sheep is deemed the Eurasian origin and migrated west to Europe and Africa and east to the Far East, in which dispersed and received selection for acclimation to autochthonic environment independently and ultimately evolved into different native breeds, respectively. Our results contribute to the comprehensive understanding of the domestic sheep origin and reveal multiple postdomestication genetic amelioration processes.     

Population structure of ALS-inhibiting herbicide-resistant Sonchus oleraceus in South Australia

Background

Annual sowthistle is a weed that is difficult to control in lentil crops in southern Australia due to a lack of herbicide options, widespread herbicide resistance and prolific production of highly mobile seed. This study investigates herbicide resistance in annual sowthistle in the Mid-North (MN) and Yorke Peninsula (YP) regions of South Australia, identifies and characterizes the mechanisms of acetolactate-synthase (ALS)-inhibitor resistance in this amphidiploid species, and combines this with analyses of population structure and gene flow.

Results

ALS-inhibitor-resistant annual sowthistle is widespread across the YP and MN of South Australia and is associated with a variety of Proline-197 mutations of the ALS gene, including leucine, alanine, arginine, serine, threonine and histidine. These mutations were found in different combinations on either of the two copies of the ALS gene. An additional 200 tissue samples were collected from across a single field on the YP and the ALS gene was sequenced for all these individuals. Different ALS-inhibitor resistance profiles were evident between mutation combinations and within mutation combinations, possibly mediated by differing subgenome assortment of the mutations, or altered gene experession of the two ALS homeologs. Population genetics analysis showed evidence of long-distance dispersal, resulting in highly mobile resistance genes, and multiple instances of resistance mutation evolution.

Conclusions

Continuing selection of Sonchus oleraceus populations with ALS-inhibiting herbicides has resulted in the accumulation of additional mutations within the ALS gene. New practices to control herbicide-resistant S. oleraceus should be examined, and control should focus on reducing seed set and dispersal to prevent the spread of emerging cases of resistance. © 2023 The Authors. Pest Management Science published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.     

中国农业科学院图书馆馆藏沿革简略

中国农科院图书馆建立已50年，但其馆藏已有70多年的历史，先后经历了日伪控制阶段、民国、新中国不同时期．本文旨在简述各时期的沿革过程及各时期的馆藏特点。     

Paleosols from the groups of burial mounds provide paleoclimatic records of centennial to intercentennial time scale: A case study from the Early Alan cemeteries in the Northern Caucasus (Russia)

Buried soil chronosequences under a series of Early Alan kurgans (burial mounds) in the Vladikavkazkaya depression of the Northern Caucasus, Russia, were studied to derive a high-resolution paleoclimatic record from the variations of the selected paleosol properties. Haplic Chernozems occur under kurgans and on the actual land surface. Three kurgan cemeteries, Brut 1, Brut 2 and Beslan, dated from the end of the second to the beginning of the seventh centuries AD have been studied. The cemeteries are situated close to each other under similar lithological and geomorphological conditions but differed in the paleosols' preservation. The Brut 2 site has been recently altered due to annual ploughing and intensive irrigation for more than 30 years. The background soils and paleosols of the Brut 2 site have been compared with synchronous soils of non-irrigated Brut 1 and Beslan sites to detect pedogenic properties that are less changed by irrigation and thus comprise the “soil memory”. Stronger black color of humus horizon, increase of humus content and decrease of humus δ¹³C values; clear signs of biological activity, absence of morphological and analytical signs of solonetz properties; diffused carbonate white soft spots in the Bca horizon and decreasing carbonate content are thought to be related to the comparatively humid climatic conditions in the region. On the contrary, relatively low humus content, tongue-like lower boundary of humus horizon, increase of humus δ¹³C values, morphological signs of solonetz properties together with high content of exchangeable Na, relatively large and clearly shaped carbonate white soft spots in the paleosols of the Brut 2 site, as well as increase of density, thickness of the carbonate pseudomicellium and high carbonate content in the upper part of profiles in the paleosols of the non-irrigated Brut 1 site are assumed to be xeromorphic features, indicating comparatively drier climatic conditions. The paleosols of the earliest chronointerval of burial (the end of the second to the beginning of the third centuries AD) demonstrate clear xeromorphic properties which indicate a relatively dry climate with a mean annual precipitation 50–100 mm less than today. The estimated duration of the period with such climatic conditions is thought to be not less than 100 years. In addition, those paleosols have some weak signs of humid conditions indicating that between the end of the first and the middle of the second centuries AD the climate was getting more moist, mean annual precipitation became equal or slightly higher than today. The paleosols buried in the first half of the fifth century AD again demonstrate the gradual enhancement of xeromorphic properties reflecting the next stage of droughts. Thus, the period with favourable humid climate when the Early Alan culture flourished in the Northern Caucasus was relatively short (about 400 years). Studying the detailed chronosequence in the non-irrigated Brut 1 site the records of intercentennial time scale soil properties variability produced by comparatively “fast” pedogenic processes typical for the steppe zone i.e., humus formation and accumulation, bioturbation, carbonate accumulation and transformation and solonetzization, have been provided.     

三探草坪的起源、演化及其概念——几种外文、外语“草坪”一词及其他

初步发掘、整理了英、德、拉丁、俄、日等五种文字、语言中草坪一词内积淀的有关草坪起源与演化的信息。三证草坪草的分化 ,草坪的起源与早期演化均属自然。人类活动于草坪中 ,认识、利用和发展了草坪 ,可以劲直、也可以曲折。人类利用草坪的方式 ,无论中、外大致相同 ,利用的水平与社会整体发展的水平大体相应。草坪由草地分化发育 ,是草地的一个特殊类型。     

ZFX、ZFY基因与动物进化关系的分析

本文对China Holstein ZFY，ZFX基因外显子片段进行克隆、测序，并利用NCBI和BLAST^(5、6、7）与Japanese black、Sheep、Horse、Pig、Human的ZFY、ZFX的同一外显子同源序列进行对比分析，结果表明：本文分析的锌指蛋白基因ZFY和ZFX外显子片段在上述各物种间，种属距离越远，种属间SNP的差异越大。对China Hoolstein及Japanese black间的ZFY、ZFX对比分析表明：同种属内不同品种间的SNP也存在差异，但同源性高于种间。同种属或品种内ZFY与ZFX的同源比较ZFY的SNP高于ZFX，ZFY在进化过程中较ZFX更活跃，而ZFX较为保守，该结果与国外多数学者的研究结果一致^[2、3、13]，对ZFY与ZFX的SNP性质进行研究发现ZFY中的碱基颠换率为16．22％、ZFX为16％．本文结果可作为奶牛胚胎早期性别鉴定的基础方法。