Trait selection in avians

Abstract

The present invention relates to transgenic avians and the eggs produced therefrom wherein the eggs comprise a genetic modification that facilitates in ovo gender sorting and a genetic modification that increases a production trait in the eggs or the avians produced therefrom. The present invention also relates to methods of identifying the gender of eggs before hatching and methods of sorting the eggs based on gender before hatching.

1 .- 41 . (canceled) 
     
     
         42 . A method of producing a gene edited female chicken lacking an exogenous polynucleotide encoding an RNA-guided engineered nuclease (RGEN), the method comprising
 a) obtaining an egg from a cross between
 i) a female chicken having a Z chromosome having a first exogenous polynucleotide integrated into the Z chromosome which encodes a marker detectable in an egg, a second exogenous polynucleotide integrated into the Z chromosome which encodes an RNA-guided engineered nuclease (RGEN), and a third second exogenous polynucleotide integrated into the Z chromosome which encodes an RNA guide for the RGEN, and a site in its genome edited by the guide and RGEN, and 
 ii) a male chicken lacking the Z chromosome and having the edited genome, 
   b) screening the egg for the marker,   c) discarding the egg if it has the marker, or selecting the egg if it does not have the marker, wherein the discarded egg is male or the selected egg is female.   
     
     
         43 . The method of  claim 42  which further comprises incubating a selected egg to produce a female chicken. 
     
     
         44 . The method of  claim 42  which further comprises screening the male and/or female chicken for the edited genome before the cross. 
     
     
         45 . The method of  claim 42 , wherein the marker is a fluorescent protein or a luminescent protein. 
     
     
         46 . The method of  claim 45 , wherein the fluorescent protein is Enhanced green fluorescent protein (EGFP) or a Red fluorescent protein (RFP). 
     
     
         47 . The method of  claim 45 , wherein the fluorescent protein is a Red fluorescent protein (RFP). 
     
     
         48 . The method of  claim 42 , wherein the RGEN is Cas3, Cas9 or Cas10. 
     
     
         49 . The method of  claim 42 , wherein the RGEN is Cas9. 
     
     
         50 . The method of  claim 42 , wherein the exogenous polynucleotides are in a single exogenous genetic construct. 
     
     
         51 . The method of  claim 42 , wherein the marker is detectable within two days of the point of lay without disrupting the integrity of the shell of the egg.