We propose to study the environmental dependence of IR properties
 of spiral/Irr galaxies by observing with ISO (ISOCAM, PHOT & LWS)
 a complete sample (mp<15.7) of 20 late-type galaxies in the  Coma
 and  A1367  clusters.   These  galaxies show evidence for ongoing
 dynamical interaction with  the  intracluster  medium.  They  are
 selected for having 1) very blue color index (B-H<2.75) and/or 2)
 pronounced asymmetries  in  their  radio  (continuum  and/or  HI)
 and/or H alpha surface brightness distributions. These properties
 can be coherently interpreted in  the  framework  of  the  "drag"
 model,  i.e.  assuming that these galaxies are currently entering
 the cluster environment, hence  experiencing  ram-pressure.   The
 interaction  is removing their HI gas on the "up-stream" side, or
 transforming it efficiently into H2, hence producing star  bursts
 in  supergiant  HII regions. On the shocked "up-stream" interface
 the radio continuum emissivity is also  enhanced,  while  on  the
 "down-stream"  side the magnetic field is stretched, forming long
 (>30 kpc) low brightness radio  continuum  trails.  By  observing
 these  20 galaxies with ISO we hope determining: 1) the distribu-
 tion of the hot dust, hence  indirectly  of  the  young,  massive
 stars  (to be compared with the results of H alpha observations),
 and the spatial distribution of PAHs heated by  their  radiation.
 2) Spectrophotometry with LWS (158 micron) will ensure the deter-
 mination of the global CII line emission, which  is  expected  to
 originate  mainly  from  the  massive star forming regions. 3) To
 check if the dynamical pressure has  observable  consequences  on
 the dust distribution, spectrophotometric measurements in 6 bands
 (PHOT 60-200 micron) will provide the relative intensities of the
 various types of dust emitting at different temperatures. The CII
 and continuum measurements will be compared with similar measure-
 ments of isolated galaxies.