Component of the PAF1 complex which is a multifunctional complex involved in transcription initiation via genetic interactions with TATA-binding proteins, elongation and transcription-coupled histone modification (By similarity). Ctr-9 is required for epidermal microtubule organization during morphogenesis (PubMed:24721716). Component of the PAF1 complex which consists of at least cdc-73, ctr-9, leo-1, pafo-1 and rtfo-1. RNAi-mediated knock-down is mostly embryonic lethal. Embryogenesis proceeds more slowly, with embryos displaying defects in the positioning and shape of epidermal cells. Randomly orientated microtubules are present in epidermal cells during the epidermal elongation process. F-actin accumulation is visible at the leading edge during ventral closure and circumferential actin bundles are present in epidermal cells. Decreased expression of pafo-1, increased cytoplasmic expression of leo-1 and increased nuclear expression of rtfo-1.