Spectrum of Cytogenomic Abnormalities Revealed by Array Comparative Genomic Hybridization on Products of Conception Culture Failure and Normal Karyotype Samples

Approximately 30% of pregnancies after implantation end up in spontaneous abortions, and 50% of them are caused by chromosomal abnormalities. However, the spectrum of genomic copy number variants （CNVs） in products of conception （POC） and the underlying gene- dosage-sensitive mechanisms causing spontaneous abortions remain largely unknown. In this study, array comparative genornic hybridiza- tion （aCGH） analysis was performed as a salvage procedure for 128 POC culture failure （POC-CF） samples and as a supplemental procedure for 106 POC normal karyotype （POC-NK） samples. Chromosomal abnormalities were detected in 10% of POC-CF and pathogenic CNVs were detected in 3.9% of POC-CF and 5.7% of POC-NK samples. Compiled results from this study and relevant case series through a literature review demonstrated an abnormality detection rate （ADR） of 35% for chromosomal abnormalities in POC-CF samples, 3.7% for pathogenic CNVs in POC-CF samples, and 4.6% for pathogenic CNVs in POC-NK samples. Ingenuity Pathway Analysis （IPA） was performed on the genes from pathogenic CNVs found in POC samples. The denoted primary gene networks suggested that apoptosis and cell proliferation pathways are involved in miscarriage. In summary, a similar spectrum of cytogenomic abnormalities was observed in POC culture success and POC-CF samples. A threshold effect correlating the number of dosage-sensitive genes in a chromosome with the observed frequency of autosomai trisomy is proposed. A rationalized approach using firstly fluorescence in situ hybridization （FISH） testing with probes of chromosomes X/Y/ 18, 13/21, and 15/16/22 for common aneuploidies and polyploidies and secondly aCGH for other cytogenomic abnormalities is recommended for POC-CF samples.

Specialized digestive adaptations within the hindgut of a colobine monkey

In mammal herbivores,fiber digestion usually occurs predominantly in either the foregut or the hindgut.Reports of mechanisms showing synergistic function in both gut regions for the digestion of fiber and other nutrients in wild mammals are rare because it requires integrative study of anatomy,physiology,and gut microbiome.Colobine monkeys(Colobinae)are folivorous,with high-fiber foods fermented primarily in their foreguts.