A Resource for the Conditional Ablation of microRNAs in the Mouse

Chong Yon Park,Lukas T Jeker,Karen Carver-Moore,Alyssia Oh,Huey Jiin Liu,Rachel Cameron,Hunter Richards,Zhongmei Li,David Adler,Yuko Yoshinaga,Maria Martinez,Michael Nefadov,Abul K Abbas,Art Weiss,Lewis L Lanier,Pieter J De Jong,Jeffrey A Bluestone,Deepak Srivastava,Michael T Mcmanus

doi:10.1016/j.celrep.2012.02.008

Abstract

The importance of miRNAs during development and disease processes is well established. However, most studies have been done in cells or with patient tissues, and therefore the physiological roles of miRNAs are not well understood. To unravel in vivo functions of miRNAs, we have generated conditional, reporter-tagged knockout-first mice for numerous evolutionarily conserved miRNAs. Here, we report the generation of 162 miRNA targeting vectors, 64 targeted ES cell lines, and 46 germline-transmitted miRNA knockout mice. In vivo lacZ reporter analysis in 18 lines revealed highly tissue-specific expression patterns and their miRNA expression profiling matched closely with published expression data. Most miRNA knockout mice tested were viable, supporting a mechanism by which miRNAs act redundantly with other miRNAs or other pathways. These data and collection of resources will be of value for the in vivo dissection of miRNA functions in mouse models.

Highlights

With the completion of the mouse and human genome sequencing, attention has shifted to deciphering the function of individual genes systematically to better understand human diseases
In 2007, these programs were consolidated under the International Knockout Mouse Consortium (IKMC) to facilitate these efforts more effectively (Skarnes et al, 2011)
The last decade has seen a surge of interest in microRNAs, given their roles in developmental and disease processes

Summary

Introduction

With the completion of the mouse and human genome sequencing, attention has shifted to deciphering the function of individual genes systematically to better understand human diseases. Genome-wide gene targeting knockout approaches were taken for proteincoding genes by multiple programs including KOMP, EUCOMM, and NorCOM (Austin et al, 2004; Auwerx et al, 2004; Collins et al, 2007; Friedel et al, 2007). Only protein-coding genes were included in this global effort because noncoding RNA gene knockouts had not captured the same level of attention at that time. The last decade has seen a surge of interest in microRNAs (miRNAs), given their roles in developmental and disease processes. These small RNAs of about 22 nucleotides can bind to target mRNAs based on sequence complementarity and direct posttranscriptional regulation of target gene expression. MiRNA knockout mice might be expected to exhibit visible phenotypes, including developmental abnormalities and embryonic lethality

Results

Discussion

Conclusion