DNA constructs for manufacturing bio-therapuetic polypeptides for use in animal vaccines and therapeutics

A nucleic acid construct for producing double stranded RNA (dsRNA), the nucleic acid construct comprising:

• a) a heterologous nucleotide sequence operably linked to a 5′ untranslated region (5′UTR), a constitutively active promoter selected from the group consisting of a 16s rrn promoter, an atpB promoter, an atpF promoter, a tufA promoter, a rbcL promoter, and a psaA promoter, and a 3′ untranslated region (3′UTR), wherein transcription of the heterologous nucleotide sequence produces interfering double stranded RNA (dsRNAi);
• and
• b) a 5′ recombination sequence at a 5′ end of the construct and a 3′ recombination sequence at a 3′ end of the construct, wherein the recombination sequences are configured for homologous recombination into a genome of a microalgal host cell, further wherein the 5′UTR is between the 5′ recombination sequence and the promoter, and the 3′UTR is between the heterologous nucleotide sequence and the 3′ recombination sequence;
• further wherein:
• the 5′UTR is selected from the group consisting of SEQ ID NO:
• 19, SEQ ID NO:
• 20, SEQ ID NO:
• 21, SEQ ID NO:
• 22, SEQ ID NO:
• 23, SEQ ID NO:
• 24, SEQ ID NO:
• 25, and SEQ ID NO:
• 26;
• and
• the 3′UTR is selected from the group consisting of a rbcL 3′UTR, a 16s rrn 3′UTR, an atpA 3′UTR, and a psA 3′UTR.