Zoological Research

365-372

Authors: Li Xiao-Hui , Zhang Juan , Li Ding-Feng , Wu Wei , Xie Zhong-Wen , Liu Qiang

Exosomes are small vesicles secreted by all cell types in the brain and play a role in cell-cell communication through the transfer of cargo or encapsulation. Exosomes in the brain have considerable impact on neuronal development, activation, and regeneration. In addition, exosomes are reported to be involved in the onset and propagation of various neurodegenerative diseases. In this review, we discuss the content of exosomes derived from major cell types in the brain, and their function under physiological and pathological conditions.

381-394

Authors: Lu Qing-Bo , Sun Jian-Fei , Yang Qu-Yang , Cai Wen-Wen , Xia Meng-Qin , Wu Fang-Fang , Gu Ning , Zhang Zhi-Jun

Magnetic brain stimulation has greatly contributed to the  advancement  of  neuroscience.  However, challenges remain in the power of penetration and precision of magnetic stimulation, especially in small animals.  Here,  a  novel  combined  magnetic stimulation system (c-MSS) was established for brain stimulation in mice. The c-MSS uses a mild magnetic pulse sequence and injection of superparamagnetic iron oxide (SPIO) nanodrugs to elevate local cortical susceptibility.  After  imaging  of  the  SPIO nanoparticles  in  the  left  prelimbic  (PrL)  cortex  in mice,  we  determined  their  safety  and  physical characteristics.  Depressive-like  behavior  was established  in  mice  using  a  chronic  unpredictable mild  stress  (CUMS)  model.  SPIO  nanodrugs  were then delivered precisely to the left PrL cortex using in situ injection.  A  0.1 T  magnetic  field  (adjustable frequency)  was  used  for  magnetic  stimulation  (5 min/session,  two  sessions  daily).  Biomarkers representing  therapeutic  effects  were  measured before and after c-MSS intervention. Results showed that  c-MSS  rapidly  improved  depressive-like symptoms in CUMS mice after stimulation with a 10 Hz  field  for  5  d,  combined  with  increased  brain- derived neurotrophic factor (BDNF) and inactivation of  hypothalamic-pituitary-adrenal  (HPA)  axis function,  which  enhanced  neuronal  activity  due  to SPIO nanoparticle-mediated effects. The c-MSS was safe and effective, representing a novel approach in the selective stimulation of arbitrary cortical targets in small  animals,  playing  a  bioelectric  role  in  neural circuit regulation, including antidepressant effects in CUMS mice. This expands the potential applications of  magnetic  stimulation  and  progresses  brain research towards clinical application.

410-422

Authors: Wang Lu-Ying , Liu Zi-Xu , Zhao Ling-Min , Huang Li-Xing , Qin Ying-Xue , Su Yong-Quan , Zheng Wei-Qiang , Wang Fan , Yan Qing-Pi

Pseudomonas plecoglossicida is  a  rod-shaped, gram-negative  bacterium  with  flagella.  It  causes visceral  white  spot  disease  and  high  mortality  in Larimichthys crocea during  culture,  resulting  in serious economic loss. Analysis of transcriptome and quantitative  real-time  polymerase  chain  reaction (PCR) data showed that dksA gene expression was significantly up-regulated after 48 h of infection with Epinephelus coioides (log2FC=3.12, P<0.001). RNAi of five shRNAs significantly reduced the expression of dksA in P. plecoglossicida,  and  the  optimal silencing  efficiency  was  96.23%.  Compared  with wild-type strains, the symptoms of visceral white spot disease in L. crocea infected with RNAi strains were reduced,  with  time  of  death  delayed  by  48  h  and mortality reduced by 25%. The dksA silencing led to a substantial down-regulation in cellular component-, flagellum-, and ribosome assembly-related genes in P. plecoglossicida, and the significant up-regulation of fliC may be a way in which virulence is maintained in P. plecoglossicida.  The  GO  and  KEGG  results showed that RNAi strain infection in L. crocea led to the down-regulation of inflammatory factor genes in immune-related  pathways,  which  were  associated with  multiple  immune  response  processes.  Results also showed that dksA was a virulence gene in P. plecoglossicida. Compared with the wild-type strains, RNAi  strain  infection  induced  a  weaker  immune response in L. crocea.

431-436

Authors: Lan Yue , Wang Jiao , Yang Qiao , Tang Rui-Xiang , Zhou Min , Lei Guang-Lun , Li Jing , Zhang Liang , Yue Bi-Song , Fan Zhen-Xin

During the breast-feeding period, infants undergo remarkable changes,  including  rapid  physiological  and  developmental growth.  However,  little  is  known  about  gene  expression features  and  sex-specific  gene  expression  in  breast-feeding infants. In this study, we sequenced 32 blood transcriptomes from  16  breast-feeding  rhesus  macaque  (Macaca mulatta) infants  and  their  lactating  mothers.  We  identified  218 differentially  expressed  genes  (DEGs)  between  infants  and mothers,  including  91  up-regulated  and  127  down-regulated DEGs in the infant group. Functional enrichment analysis of the  up-regulated  DEGs  and  unique  hub  genes  in  infants showed  primary  enrichment  in  immunity,  growth,  and development.  Protein-protein  interaction  analysis  also revealed  that  genes  at  key  positions  in  infants  were  mainly related  to  development  and  immunity.  However,  we  only detected 23 DEGs between female and male infants, including three DEGs located on chromosome X and 14 DEGs located on chromosome Y. Of these DEGs, TMF1 regulated nuclear protein  1  (Trnp1),  which  was  highly  expressed  in  female infants,  is  crucial  for  controlling  the  tangential  and  radial expansion of the cerebral cortex in mammals. Thus, our study provides  novel  insight  into  the  gene  expression  features  of breast-feeding  infants  in  non-human  primates  (NHPs)  and reveals sex-specific gene expression between these infants.

444-448

Authors: Li Zhen-Hui , He Xia-Ping , Li Hao , He Rong-Qiao , Hu Xin-Tian

Rhesus monkeys (Macaca mulatta) are valuable experimental animals  for  studies  on  neurodegenerative  diseases  due  to their evolutionarily close relationship to humans (Zhang et al., 2014).  Rhesus  monkeys  also  display  similar  hallmarks  of aging and neurodegeneration as humans, including formation of senile plaques in the brain (Beckman et al., 2019; Paspalas et al., 2018). However, changes in formaldehyde (FA) levels in the cerebrospinal fluid (CSF) of rhesus monkeys with aging have not been reported. Additionally, whether changes in CSF FA  are  correlated  with  changes  in  amyloid-β  (Aβ) concentrations  have  not  yet  been  explored.  Here,  the  CSF levels  of  Aβ40,  Aβ42,  and  FA  were  measured  in  56  rhesus monkeys  of  different  ages,  ranging  from  4  to  26  years  old. Results revealed significant declines in Aβ40 and Aβ42, and an increase  in  FA  with  age.  Interestingly,  the  increase  in  FA levels  was  negatively  correlated  with  Aβ40 and  Aβ42 concentrations in aged rhesus monkeys but not in young and middle-aged  monkeys.  These  results  appear  to  parallel changes seen within human aging, i.e., decreased levels of CSF Aβ and increased levels of FA in normal aged adults and Alzheimer’s  disease  (AD)  patients.  These  findings  further indicate that rhesus monkeys are a reliable model for studying age-related  neurological  disorders  such  as  AD  and  suggest that FA is an important factor in AD development and may be used as a diagnostic indicator of such disease.

455-457

Authors: Zhao Hai-Tao , Zhang Wen-Qing , Jia Kang-Sheng , Li Jia-Xuan , Bai Xu-Xiang , Wang Xiao-Wei , Guo Song-Tao , He Shu-Jun , Sun Hong-Juan , Lei Ying-Hu , Pan Ru-Liang , Li Bao-Guo

Infanticide  by  unrelated  individuals  is  widely  reported  in  the animal  kingdom;  however,  little  is  known  about  cases perpetrated by a parent, particularly the mother. This article reports on three cases of mother-initiated infanticide in Qinling golden  takins  (Budorcas taxicolor bedfordi)  from  video  and camera images. Based on previous reports in other animals, we  propose  that  the  infanticide  events  observed  in  golden takins were related to the parental manipulation mechanism – i.e., killing an unhealthy infant to allow the mother to invest more  care  in  potentially  healthy  offspring,  and  gain  more fruitful  reproductive  opportunities.  This  appears  to  be  an evolutionary-based selection strategy, whereby a species can prosper  and  succeed  under  the  challenges  of  natural selection. However, further studies on both captive and wild populations  are  required  to  answer  the  various  questions raised from our observations.

465-470

Authors: Feng Chen-Guang , Zhang Yu , Tong Chao , Zhou Bing-Zheng , Li Xiao-Hui , Tang Yong-Tao , Song Wen-Zhu , Zhao Kai

A new species of Tibetan loach, Triplophysa weiheensis sp. nov., is described from the Weihe River in Gansu Province, China, based on morphological and molecular analyses. The new species can be distinguished from all known congeners by a unique combination of the following characters: scaleless; snout abruptly sloping downward, anterior to anterior nostril; lower jaw crescentic, not sharp; body without obvious mottling; lateral  line  interrupted  on  posterior  trunk  at  pelvic-fin  distal extremity;  caudal-peduncle  length  2.0–2.7  times  its  depth; branched rays of pectoral fin 10–11; branched rays of pelvic fin  5–6;  inner  gill  rakers  on  1st gill  arch  14–16;  vertebrae 4+34–36;  intestine  with  6–7  loops,  length ca. 1.8  times  SL (n=3);  bony  capsule  of  air  bladder  small  and  thin;  posterior chamber of air bladder absent.