Table 1

Respiratory parameters and anatomical measures of wild-type, heterozygous and homozygous Hoxa2 mutant mice at birth


Wild-type
Heterozygous
Homozygous

Respiratory and behavioral parameters at P0.1



N
38
58
29
Birth weight (g)
1.45 ± 0.006
1.46 ± 0.022
1.40 ± 0.024
Weight gain at P0.75



     Grams
0.24 ± 0.01
0.22 ± 0.01
-0.09 ± 0.008*
     Percent
16.5 ± 1.0
15.1 ± 0.9
-6.6 ± 0.6*
Jaw openings (in 30 s)
24.0 ± 0.41
23.9 ± 1.22
13.6 ± 1.63*
fR (cycles/minute)
107 ± 1.3
107 ± 4.0
110 ± 5.7
Tidal volume (μl/g)
4.6 ± 0.06
5.3 ± 0.41
10.6 ± 0.87*
VE (ml/g/minute)
0.52 ± 0.01
0.58 ± 0.06
1.21 ± 0.14*
Apneas (% of recording duration)
11 ± 0.8
9.6 ± 3.0
8.1 ± 3.7
Anatomical measures



N
8
4
12
AP length of locus coeruleus (μm)
455 ± 18
420 ± 60
717 ± 23*
DV height of locus coeruleus (μm)
625 ± 60
700 ± 20
1,017 ± 73
Distance between LC ventral limit (μm)
1,050 ± 25
Not measured
607 ± 79*

Values are given as mean ± standard error of the mean. fR, respiratory frequency; VE, minute ventilation. Tidal volume at birth was increased two-fold in Hoxa2-/- mice (see also Figure 2), but this feature disappeared rapidly: VE at P0.75 was not significantly different between the three genotypes. Note that Hoxa2-/- mice lost weight between birth and P0.75, while their wild-type and heterozygous littermates gained weight. The birth weight and respiratory frequency are not significantly different. *P < 0.001; P < 0.01. DV, dorso-ventral; LC, locus coeruleus.

Chatonnet et al. Neural Development 2007 2:19   doi:10.1186/1749-8104-2-19