Identification of maternal-effect genes in zebrafish using maternal crispants

Area of Science:

• Developmental Biology
• Genetics
• Molecular Biology

Background:

• Early animal development relies on maternal factors (RNA and proteins) for cellular processes and differentiation before zygotic gene activation.
• The functions of many maternally expressed factors remain largely unknown.
• Understanding these maternal factors is critical for deciphering the initial stages of embryonic development.

Purpose of the Study:

• To develop and validate a rapid method for identifying and characterizing maternal-effect genes.
• To leverage CRISPR-Cas9 technology for efficient genetic analysis in a single generation.
• To discover novel maternal-effect genes in zebrafish.

Main Methods:

• Utilized CRISPR-Cas9 gene editing to create biallelic mutations in maternal germ lines (maternal crispants).
• Phenotypically validated the technique by replicating known maternal-effect gene mutations (birc5b, tmi, mid1ip1).
• Sequenced haploid progeny from F0 females to confirm genetic identity and analyze induced mutations.

Main Results:

• Successfully generated maternal crispants that phenocopied known maternal-effect genes.
• Identified two novel maternal-effect zebrafish genes: kpna7 and fhdc3.
• Demonstrated the effectiveness of maternal crispants for rapid gene identification and characterization.

Conclusions:

• Maternal crispants provide an effective strategy for the rapid identification and primary characterization of maternal-effect genes.
• This technique facilitates reverse genetics analysis of maternal factors essential for embryonic development.
• The study advances the understanding of genetic control during early development.