Biology subjects

Ai, H.

Publications and source records attributed to Ai, H..

4 recordsLinked to original sources

bioRxiv2018

A segmentation scheme for complex neuronal arbors and application to vibration sensitive neurons in the honeybee brain

The morphology of a neuron is strongly related to its physiological properties, and thus to information processing functions. Optical microscope images are widely used for extracting the structure of neurons. Although several approaches have been proposed to trace and extract complex neuronal structures from microscopy images, available methods remain prone to errors. In this study, we present a practical scheme for processing confocal microscope images and reconstructing neuronal structures. We evaluated this scheme using image data samples and associated gold standard reconstructions from the BigNeuron Project. In these samples, dendritic arbors belonging to multiple projection branches of the same neuron overlapped in space, making it difficult to automatically and accurately trace their structural connectivity. Our proposed scheme, which combines several software tools for image masking and filtering with an existing tool for dendritic segmentation and tracing, outperformed state-of-the-art automatic methods in reconstructing such neuron structures. For evaluating our scheme, we applied it to a honeybee local interneuron, DL-Int-1, which has complex arbors and is considered to be a critical neuron for encoding the information indicated in the waggle dance of the honeybee.

bioinformatics↗

bioRxiv2017

Development of honeybee waggle dance and its differences between recruits and scouts

The lifetime development of the waggle dance of 14 honeybees was automatically recorded just after the imaginal molt using high-definition camera modules connected with a Raspberry Pi computer and numbered radio-frequency identification tags fitted to the back of each bee. For most honeybees, waggle dance follow preceded the appearance of the first waggle dance from 1 week after the imaginal molt. The duration per trip increased just after waggle dance follow. Before the appearance of the first waggle dance, the honeybee repeatedly follows waggle dances that indicate a limited number (2-6) of food source locations. We discriminated between two types of foragers with different roles, recruits and novice scouts, by comparing the vectors indicated by the bees first waggle dance (sending vectors) with dances they had previously followed (received vectors). Of 14 tagged honeybees, 11 were categorized as recruits and 2 as novice scouts. For recruits (but not for novice scouts), the duration per trip increased significantly after waggle dances follow and substantially increased just before the appearance of the first waggle dance. Moreover, recruits increased the number of times they followed waggle dances indicating the same location, and their first waggle dance indicated this location. These results suggest that the differentiation of these two types of foragers is partly related to behavioral differences after waggle dance follows: whether trip is activated or not by follows a waggle dance.\n\nSummary statementBecause of technological difficulties, there are no studies comparing the development of recruit and scout waggle dances. Using miniature radio frequency identification tags, we observed and clarified these developmental processes.\n\nList of Abbreviations

animal behavior and cognition↗

bioRxiv2017

Network simulations of interneuron circuits in the honeybee primary auditory center

Processing of airborne vibration signals in the auditory system is essential for honeybee communication through the waggle dance language. Properties of neurons in the honeybee primary auditory center suggest a circuitry of excitatory and inhibitory neurons encoding these communication signals. To test this assumption, we simulated this network and analyzed the predicted responses for different types of inputs. In particular, we investigated the effect of specific inhibitory connections in the network. The results indicate that the experimentally observed responses of certain interneuron types are compatible with an inhibitory network of vibration processing in the primary auditory center of the honeybee.

bioinformatics↗

bioRxiv2017

The Y-Chromosome Clarifies The Evolutionary History Of Sus scrofa By Large-Scale Deep Genome Sequencing

The genetics and evolution of sex chromosomes are largely distinct from autosomes and mitochondrial DNA (mtDNA). The Y chromosome offers unique genetic perspective on male-line inheritance. Here, we uncover novel evolutionary history of Sus scrofa based on 205 high-quality genomes from worldwide-distributed different wild boars and domestic pig breeds. We find that only two haplotypes exist in the distal and proximal blocks of at least 7.7 Mb on chromosome Y in pigs across European and Asian continents. And the times of most recent common ancestors (TMRCA) within both haplotypes, approximately 0.14 and 0.10 million years, are far smaller than their divergence time of around 1.07 million years. Whats more, the relationship between Sumatran and Eurasian continent Sus scrofa is much closer than that we knew before. And surprisingly, European pigs share the same haplotype with many Chinese pigs, which is not consistent with their deep splitting status on autosome and mtDNA. Further analyses show that the haplotype in Chinese pigs was likely introduced from European wild boars via ancient gene flow before pig domestication about 24k years ago. Low mutation rates and no recombination in the distal and proximal blocks on chromosome Y help us detect this male-driven ancient gene flow. Taken together, our results update the knowledge of pig demography and evolution, and might shed insight into the genetics and evolution studies on chromosome Y in other mammals.

evolutionary biology↗