Table 1. Strains and plasmids used and/or constructed in this work.

	Genotype or Relevant Feature	Reference or Source
Strains:
E. coli
DH-5alpha	F- φ80d lacZΔM15Δ (lacZY-argF) U169 deoR recA1 endA1 hsdR17(rk- mk+) phoA supE44l- thi-1 gyrA96 relA1.	[35]
X. dendrorhous
UCD 67–385	ATCC 24230, wild-type. Diploid strain [55].	ATCC
CBS 6938	ATCC 96594, wild type.	ATCC
CBSTr	crtR - mutant strain from CBS 6938 parental wild-type strain. Hygromycin B resistant mutant.	[22]
CBS-cbr.1-	cbr.1- mutant strain from CBS 6938 parental wild-type strain. Hygromycin B resistant mutant.	This work
CBS-cbr.2-	cbr.2- mutant strain from CBS 6938 parental wild-type strain. Zeocin resistant mutant.	This work
Plasmids:
pBluescript SK- (pBS)	ColE1 ori; AmpR; cloning vector with blue-white selection.	Stratagene
pMN-hph	pBS contained at the EcoRV site a cassette of 1.8 kb bearing the E. coli-Hygromycin B resistance (hph) gene under EF-1 α promoter and the GPD transcription terminator of X. dendrorhous.	[56]
pIR-zeo	pBS contained at the EcoRV site a cassette of 1.2 kb bearing the Streptoalloteichus hindustanus Zeocin resistance Sh ble gene under the EF-1 α promoter and GPD transcription terminator of X. dendrorhous.	[18]
pXd-gCBR.1::hph	pBS contained at the EcoRV, 865 pb upstream, 750 pb downstream of the CBR.1 gene and the hygromycin B resistance cassette between them.	This work
pXd-gCBR.2::zeo	pBS contained at the EcoRV, 677 pb upstream, 803 pb downstream of the CBR.2 gene and the zeocin resistance cassette between them.	This work

ATCC: American Type Culture Collection.