Abstract—Reproductive capacity declines with aging, thereby increasing errors in fertilization, chromosome segregation, and embryonic cleavage. Age-related changes in oocytes involve not only function but also appearance. We previously showed that the texture of the cytoplasm in Caenorhabditis elegans oocytes varies with their age. We quantitatively characterized this change by evaluating two image features: Mm Value (mean difference between the maximum and minimum intensities within each moving window) and Correlation (COR), which is based on the Gray Level Co-occurrence Matrix (GLCM). However, the association between genetics and changes in cytoplasmic texture with aging has not been clarified. Genes that cause texture changes similar to those observed during oocyte aging are candidates for involvement in the aging pathway. Here, to examine whether gene knockdown of specific genes can change the Mm Value or COR, we analyzed the cytoplasmic texture in images from the Worm Developmental Dynamics Database 2. This database stores differential interference contrast microscopy images of early C. elegans embryos with genes silenced by RNA-mediated interference. Of 316 target genes screened, we identified five genes (smc-4, F10C2.4, tin-44, let-754, hmp-2) whose knockdown decreased the Mm Value and one gene (csr-1) whose knockdown increased the COR. The five genes included genes involved in age-related function, such as chromosome segregation and mitochondrial function, and some genes that are not known to be related to aging. The gene that increased the COR is also involved in chromosome segregation. Our findings indicate that these six genes could potentially be involved in reproductive aging.

Index Terms—Caenorhabditis elegans, image texture analysis, Nomarski DIC microscopy, RNAi screening, statistical image processing, reproductive aging.

Momoko Imakubo is with Graduate School of System Informatics, Kobe University, Kobe, Japan. She is also with RIKEN Center for Biosystems Dynamics Research, Kobe, Japan.
Koji Kyoda and Hiroya Itoga are with RIKEN Center for Biosystems Dynamics Research, Kobe, Japan.
Jun Takayama is with RIKEN Quantitative Biology Center, Kobe, Japan.
Shuichi Onami is with Graduate School of System Informatics, Kobe University, Kobe, Japan. He is also with RIKEN Center for Biosystems Dynamics Research, Kobe, Japan. He is also with RIKEN Quantitative Biology Center, Kobe, Japan and RIKEN Quantitative Biology Center, Kobe, Japan.

Cite:Momoko Imakubo, Koji Kyoda, Hiroya Itoga, Jun Takayama, Shuichi Onami, "Texture-Based Screening to Identify Genes Involved in Reproductive Aging in Caenorhabditis elegans," International Journal of Bioscience, Biochemistry and Bioinformatics vol. 11, no. 3, pp. 40-49, 2021.

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