diff --git a/negspy/data/mm9/chromSizes.tsv b/negspy/data/mm9/chromSizes.tsv
index 7e676e8..5ac614d 100644
--- a/negspy/data/mm9/chromSizes.tsv
+++ b/negspy/data/mm9/chromSizes.tsv
@@ -1,22 +1,22 @@
-chr1    197195432
-chr2    181748087
-chr3    159599783
-chr4    155630120
-chr5    152537259
-chr6    149517037
-chr7    152524553
-chr8    131738871
-chr9    124076172
-chr10    129993255
-chr11    121843856
-chr12    121257530
-chr13    120284312
-chr14    125194864
-chr15    103494974
-chr16    98319150
-chr17    95272651
-chr18    90772031
-chr19    61342430
-chrX    166650296
-chrY    15902555
-chrM    16299
\ No newline at end of file
+chr1	197195432
+chr2	181748087
+chr3	159599783
+chr4	155630120
+chr5	152537259
+chr6	149517037
+chr7	152524553
+chr8	131738871
+chr9	124076172
+chr10	129993255
+chr11	121843856
+chr12	121257530
+chr13	120284312
+chr14	125194864
+chr15	103494974
+chr16	98319150
+chr17	95272651
+chr18	90772031
+chr19	61342430
+chrX	166650296
+chrY	15902555
+chrM	16299